Art therapy in patients with physical illnesses as a complementary psychological intervention is based on the principle that in addition to physical consequences, chronic or serious illness can affect the emotional, cognitive, and social processes of the individual, leading to anxiety, depression, helplessness, and decreased quality of life. The theoretical basis of art therapy is based on the purposeful use of creative processes to facilitate the expression of emotion, increase self-awareness, enhance adaptation, and create an experience of control. In many patients, worry about the future, physical limitations, pain, changing family and social roles, and dependence on therapy can increase psychological stress. Art therapy provides a supportive environment to express some of these experiences without being completely dependent on verbal communication. Activities such as painting, drawing, collage, working with flowers, music, and other artistic media can help a person symbolically represent and organize thoughts and feelings related to the disease. One of the possible mechanisms of this intervention is the externalization of emotion, which means that emotions such as fear, sadness, anger, and frustration are removed from the inner ambiguity and placed in a visible format. This process can provide the basis for dialogue therapy, identifying psychological needs, and increasing the sense of control. In anxiety, focusing on the creative process can direct a person's attention from constant worries to a structured and meaningful activity, increasing the opportunity to experience relaxation and presence in the moment. In depression, participation in artistic activity can be associated with an increase in purposeful activity, experience of success, expression of excitement, and a strengthened sense of competence. Research evidence in different groups with physical illnesses has shown that artistic interventions can be associated with a reduction in some indicators of anxiety and depression and an improvement in quality of life, although the effectiveness rate is not the same in different studies and depends on the type of disease, the severity of symptoms, the type of intervention, and the duration of treatment. In patients with cancer, art therapy can be used to express fear of illness, worry about treatment, change body image, and experience losses. In cardio, chronic, and debilitating diseases, art activities may also help to psychologically adapt to physical limitations and strengthen coping resources. One of the important uses of art therapy is to provide an opportunity to redefine one's identity beyond the role of the "patient," as creative activity can foster a sense of empowerment and continuity of personal identity. Participation in group art activities can also increase social interaction, a sense of belonging, and emotional support, and reduce social isolation. In hospital settings, the implementation of short-term art interventions can help reduce distress caused by hospitalization and treatment processes, but it is necessary to coordinate the type of activity with the patient's physical condition, energy level, and motor ability. Art therapy can also be used alongside standard medical and psychological therapies as part of comprehensive care and should not replace medical treatment or specialized treatment for depression and anxiety disorders. Important challenges in this area include the difference in patients' response to artistic media, the difficulty of implementing the intervention in some physical conditions, fatigue, pain, movement limitation, and differences in the level of patient participation. On the other hand, some studies have been conducted with small samples, short intervention periods, or different methodologies, which limits the generalizability of the results. The interpretation of the artwork should also be done with caution, and the therapist should not draw definitive conclusions about the patient's mental state solely on the basis of the color, shape, or content of a work. It is suggested that future studies with larger samples, a control group, long-term follow-up, and the use of validated scales of depression, anxiety, and quality of life should be investigated, and the effect of the type, intensity, and duration of art interventions should be investigated separately. Also, designing person-centered programs tailored to the type of disease, physical condition, and preferences of the patient can increase the effectiveness and participation in treatment. In general, art therapy has the potential to be used as a complementary intervention in reducing some symptoms of anxiety and depression, enhancing emotional expression, increasing adaptation, and improving the quality of life of patients with physical diseases, and its place in integrated physical psychological care becomes clearer with the continuation of more rigorous research.