Objective: The purpose of the present study is to examine the effectiveness of cognitive behavioral family therapy with an emphasis on positive psychotherapy in treating psychosomatic disorders. Method: A single subject design was applied. Three patients suffering from chronic lower back and neck pain were selected as a sample group and participated in 16 sessions of family therapy, two hours per week. Examination by a physician, X-ray and clinical interview based on DSM IV-TR along with MMPI and SCL- 90-R tests were used as instruments. Result: Almost all the subscales of MMPI and SCL-90-R and other instruments showed significant decrease after therapy as compared with the pretest results. Discussion: The results indicated the effectiveness of cognitive behavior family therapy based on positive psychotherapy. Some possible reasons could be solving conflicts and interpersonal problems by means of training certain skills such as problem solving, developing relationships with others, effective coping, assertiveness and positive thinking.