Objective: Psychotherapy is recommended concomitantly with pharmacotherapy to treat functional deterioration in patients with early-phase schizophrenia. This study aims to investigate and compare the impact of interpersonal group psychotherapy on functionality in patients with early-phase schizophrenia compared to painting therapy and waiting list groups. Methods: Prospective, single-blind, controlled study was carried out in Bolu Community Mental Health Center. The sample consists of 60 patients who had received neither rehabilitation nor psychotherapy before and who were eligible for the study. Participants were distributed consecutively to group psychotherapy, painting and waiting list groups each consisting 20 patients based on their order of admission. Therapeutic intervention was composed of 24 sessions of interpersonal group psychotherapy for 6 months. Sociodemographic Data Forms; positive and negative syndrome scales and brief functionality assessment scale were used at beginning and at the end of therapy. Results: Three groups did not differ in age, education, disease duration, number of hospitalizations, gender, working, socioeconomic and marital status, social support, pharmacological treatment's type and dose. At the end of the study, patients in group psychotherapy had much more improvement in functionality compared to the painting therapy and waiting lists groups. Discussion: Interpersonal group psychotherapy may aid as an adjunctive to treatment as usual in community mental health centers to improve functioning of patients with early-phase schizophrenia.