INTRODUCTION: Weight gain and obesity that emerge during psychopharmacologic treatment are prevalent in persons with serious and persistent mental illness. Obesity is difficult to reverse, but behavioral programs involving diet and exercise are sometimes successful. METHOD: Patients with serious and persistent mental illness living in the community were enrolled voluntarily into the Solutions for Wellness Personalized Program. Participants completed an enrollment survey that provided information for the creation of an individualized management plan that included nutrition, exercise, stress management, and sleep improvement components. Weight, body mass index (BMI, kg/m(2)), behavior, and attitudes were assessed at baseline (enrollment) and monthly for 6 months. RESULTS: During the period of July 1, 2002, through June 30, 2003, 7188 patients with serious and persistent mental illness had enrolled in the program, and 83% were either overweight or obese. Follow-up survey responses taken at 6-month endpoint from finishers (N = 1422) indicated that positive changes were made in diet (91%), exercise (85%), reduced stress (93.8%), and sleep (92.9%). Significant decreases in BMI were associated with changes in diet (p = .014) and exercise (p = .035). In addition, 97% of participants reported that they were at least somewhat confident in the ability to maintain lifestyle changes, and this confidence was significantly (p < .001) associated with reaching dietary and exercise goals. CONCLUSIONS: Patients suffering from serious and persistent mental illness may benefit from participating in wellness intervention programs.