OBJECTIVES: The long-term outpatient group psychotherapy with the chronically ill is an effective, expedient therapeutic modality that makes patients maintain medication and improve their symptoms, helps patients resolve emotional conflict, and corrects their maladaptive interpersonal relationship. Therefore, we performed weekly the semi-opened, heterogeneous, long-term(open-ended), outpatient group psychotherapy to be applicable effectively for the chronically ill. The objectives of this study are as follows; first, we introduce therapeutic principles and management methods of the group psychotherapy to be applicable in the clinical environment with the chronically ill; second, we examine the therapeutic factors in each group development stage which are helped by participants, and analyze the characteristics showed in the process of study; third, we verify the appropriateness and the validity of this group psychotherapy and then establish the base of the effective long-term outpatient therapy for the chronically ill that will be settled down as a applicable treatment modality economically and efficiently in the present medical environment of Korea. METHODS: This study was performed in the subject of the chronically ill who attended at the day care program of Community Mental Health Center in Hanam city from January 1998 to June 1999. The participants were 27 patients, but we dropped 7 patients who attended under 6 months because of long-term group. So the last subjects were 20 patients (12 males and 8 females) who attended for 18 months. The 13 therapeutic factors scale was filled out by participants just after each session and the self-report total assessment questionnaire was performed at the time of study-termination and patient-termiation. RESULTS: The ranks of 13 therapeutic factors scale are as follows: in the forming stage, the upper ranks of therapeutic factors were existential factor, guidance of therapists, instillation of hope, altruism, and catharsis in order. And in the storming stage, the upper ranks of therapeutic factors were existential factor, instillation of hope, guidance of therapists, catharsis, and group cohesiveness in order. Lastly in the norming stage, the upper ranks of therapeutic factors were existential factor, altruism, corrective recapitulation, interpersonal learning, and catharsis in order. According to the total assessment questionnaire about group psychotherapy reported by the participants 90% of them were helped, 80% of them had an idea to recommend this program to other patients actively, and 75% of them had an opinion to attend again this program if given for them. And they evaluated positively about the structure of this program and the therapist. CONCLUSIONS: The long-term outpatient group psychotherapy would be applicable effectively to the chronically ill as a economic, efficient therapeutic modality for rehabilitation. It is much more effective for therapist to perceive in detail the therapeutic factors in each group develop-ment stage when he perfoms the group psychotherapy.