The authors compared characteristics of 1,012 outpatients completing a 10-week behavioral medicine intervention with 300 outpatients who dropped out. They administered the Symptom Checklist-90 Revised (SCL-90R) before and after the program. Patients who completed the treatment, compared with dropouts, tended to be more highly educated, married, and gainfully employed. Their pretreatment scores on the SCL-90R were significantly lower than those of the dropouts on somatization, depression, and obsessive-compulsive scales and on the global severity index. Multiple logistic regression analysis indicated that lower depression and higher education marked the group who completed the intervention in contrast to the dropouts. After the intervention, all of the SCL-90R scores were significantly lower among patients who completed the treatment. Pre- to postintervention score changes were not significantly associated with the number of sessions attended. The findings suggest that the intervention had salutary effects in patients with mind/body distress and that its effectiveness was not diminished by a few absences. Depressed or less educated patients might benefit from preparatory interventions or from a modified approach to their treatment.