The aim of this study was to determine whether occupational therapy (OT) can improve the interpersonal relationships and negative symptoms of hospitalized chronic schizophrenia patients with severe negative symptoms. Subjects were 38 patients with chronic schizophrenia. They were randomly divided into an OT group and a control group. Patients in the OT group participated in cooking activities once a week for 15 weeks, while patients in the control group did not. During this period, both groups had the usual treatment except for the cooking activities. In interviews, the patient was asked to place a chair toward the interviewer (a therapist). The angle and distance from the interviewer were taken as indicators of an ability to have interpersonal relationships. Negative symptoms were evaluated with the Scale for the Assessment of Negative Symptoms (SANS). Patients who received OT were able to sit at the smaller angle and shorter distance from the interviewer than before OT (p=0.015 and p=0.013, respectively). The total SANS score was lower after OT than before OT (p=0.033). In the control group, the distance from the interviewer also decreased during the experimental period (p=0.040) but the seating angle and the SANS scores did not change. The results suggest that OT can help to improve a relationship allowing the patient to face the therapist and that it might improve negative symptoms of schizophrenia.