This study was conducted to investigate the effect of art therapy from a psychodynamic perspective on obsessive-compulsiveness and anxiety in an adult male. The participant was a 30-year-old male diagnosed with obsessive-compulsive disorder (OCD), and the art therapy was conducted once a week for 60 minutes, for a total of 23 sessions. To verify the effectiveness of art therapy, the Obsessive-Compulsive Inventory-Revised (OCI-R), State-Trait Anxiety Inventory (STAI), and house-tree-person test (HTP) were conducted before and after the treatment and the results were compared. The obsessive-compulsive scale score decreased by 9 points from 46 to 37, the state anxiety score decreased by 19 points from 73 to 54, and the trait anxiety score decreased by 11 points from 70 to 59. The comparison of the HTP showed that the pretreatment drawing symbolically expressed stress and anxiety by depicting wind, rain, and clouds with weak pen pressure, but the post-treatment drawing illustrated a scene of comfortable relaxation with strong pen pressure. Additionally, the participant voiced feelings of being tiresome, unhappy, hopeless, and wanting to run away prior to the pretreatment test but mentioned feelings of comfort and lightheartedness after the treatment, indicating positive changes. Therefore, this study suggests that art therapy can be useful as a supplementary intervention to reduce symptoms of obsessive-compulsiveness and anxiety symptoms in adults with OCD.