The role of the psycho-oncologist in guiding art therapy as a complementary intervention in the treatment of pediatric cancer is based on a multidimensional approach in which the child with cancer is not only seen as the recipient of medical treatment, but is considered as an individual experiencing physical, emotional, cognitive, familial, and social changes simultaneously. The theoretical foundations of this approach are based on the biopsychosocial model and contemporary perspectives of psycho-oncology that consider the interaction of physical illness, psychological processes, family environment, and quality of life. In this framework, art therapy can be used as a complementary intervention alongside standard oncological therapies and aims not to replace medical treatment, but rather to reduce the psychological burden of the disease and facilitate the child's adaptation to the treatment process. The psycho-oncologist plays a pivotal role in assessing the psychological state, identifying emotional needs, and determining the suitability of the art intervention to the child's condition. The importance of this role stems from the fact that children with cancer may experience anxiety, fear of medical procedures, body image disorders, feelings of lack of control, social isolation, communication problems, and concerns about separation from parents. Art can provide some children with a communication platform that is more appropriate to their level of cognitive and emotional development than verbal expression. In the theoretical foundations of child art therapy, the creative process is more important than the final product, and painting, collage, color work, visual storytelling, art construction, and other age-appropriate activities can allow for the expression of inner experiences. The psycho-oncologist determines and guides the type and intensity of artistic activity in collaboration with the art therapist, according to the child's stage of development, cognitive status, severity of symptoms, medical conditions, and capacity for participation. From the perspective of emotion regulation, artistic activity may help the child identify complex emotions such as fear, anger, sadness, and frustration and organize them in a more tolerable way. The process of creating a work can also strengthen a sense of agency and control, which is especially important in a situation where a child sees a large part of his or her daily life under the influence of medical procedures. The available research evidence in the field of art therapy and psychological care for children with physical illnesses shows that artistic interventions have been associated with a reduction in anxiety, psychological distress, and tension associated with therapeutic measures in some studies, although the quality of the studies, the type of intervention, the sample size, and the evaluation tools are not the same in the researches. The research findings also support the view that artistic activities can create a good opportunity for a child to interact with parents, therapists, and members of the treatment team. In a hospital setting, art may help reduce the monotony of the inpatient experience and create meaningful activity across medical processes. Some studies in the field of art interventions in children with cancer have reported improvements in indicators such as mood, participation, social interaction, and a child's subjective experience of the treatment process, but these findings should not be interpreted as demonstrating a direct effect of art therapy on tumor control or substitution of cancer treatment. The role of the psycho-oncologist in interpreting this evidence is of fundamental importance, as a scientific distinction must be made between the psychological and biological consequences of the disease. In clinical application, the first step is to comprehensively assess the child in terms of psychological distress, anxiety, depression, fear, adjustment problems, quality of family relationship, and developmental conditions. Once assessed, the goals of art therapy should be tailored to the child's individual needs and can include facilitating emotion expression, increasing a sense of control, strengthening communication, reducing tension, supporting adjustment, and maintaining the child's identity outside of the patient's role. The psycho-oncologist can play a specialized liaison role in coordination between the oncologist, psychologist, art therapist, nurse, and family. This interdisciplinary collaboration is especially important when the child is undergoing chemotherapy, radiation therapy, or other systemic treatments, and his or her physical condition may change from one day to the next. The art program should be adapted to the child's clinical circumstances, energy levels, pain, nausea, fatigue, limited movement, and infectious health needs. In young children, play and art can be combined to allow for indirect expression of the experience of illness. In older children and adolescents, activities such as identity imagery, personal art book, visual narrative of illness, or the creation of digital works can be tailored to their developmental and identity needs. The psycho-oncologist can also use art therapy to address body image changes caused by hair loss, weight changes, surgery, or other treatment outcomes, without forcing the child to express or confront an issue for which he or she is not psychologically prepared. Another important application is the use of art activities to strengthen the child's connection with the parents; parents can participate in some joint activities and gain more opportunity to observe the child's feelings and needs through the development process. In such a situation, art does not become a standalone diagnostic tool, but rather is used as a complementary communication channel alongside clinical interviews and validated psychological assessments. It is suggested that art interventions in pediatric cancer centers be designed in the form of specific, flexible, and evidence-based protocols, with goals, duration, number of sessions, evaluation indicators, and discontinuation criteria predetermined. Specialized training of art therapists on the characteristics of pediatric cancer, principles of infection control, treatment-related fatigue, and collaboration with the oncology team can also increase the safety and quality of interventions. The psycho-oncologist should also monitor the child's emotional state and change the goals of the intervention during treatment. The use of validated tools to measure distress, anxiety, quality of life, and adjustment can help to more accurately assess the outcomes of the intervention. Important challenges in this area include the heterogeneity of children's clinical conditions, age and developmental differences, cultural differences in families, and time constraints in the hospital setting. Some children may not be able to actively participate in artistic activities due to pain, fatigue, or poor physical condition. Another limitation is the heterogeneity of art therapy methods in the existing research, which makes it difficult to compare the results directly. The small sample size, the lack of a suitable control group in some studies, and the difference in measurement tools are also significant methodological limitations. In addition, overinterpreting drawings and attributing fixed and definite meanings to pictorial elements can lead to clinical errors, and therefore the content of the work should be examined in the context of dialogue, observation of behavior, and the therapist's prior knowledge of the child. Art therapy should also not become a tool to force the child to disclose difficult emotions, as the principle of choice, choice, and a sense of psychological security should be maintained at all stages. It is suggested that future research use controlled designs, larger samples, long-term follow-up, and multidimensional indicators to determine more accurately the true effectiveness of these interventions. Examining the differences in the effectiveness of visual arts, music, drama, storytelling, and integrated methods can also help to personalize interventions. Finally, the role of the psycho-oncologist in guiding art therapy can be considered as a coordinating, evaluator, observer, and therapist-centered role, with the main goal of placing artistic activity in a safe clinical framework based on the child's needs. In this model, art is not an independent cancer treatment, but a means to support a child's mental health, communication, adjustment, and quality of life alongside standard oncological care, and its value increases when it is accompanied by rigorous evaluation, interdisciplinary collaboration, ethical principles, and scientific evidence.