Purpose: The purpose of this study was to examine the effects of an aerobic exercise program on body mass index,mood state, and psychiatric symptoms in men with chronic schizophrenia. Methods: Non-equivalent control grouppretest and posttest design was used. The participants were men with chronic schizophrenia hospitalized in Nmental hospital located in N city (29 in the experimental group and 30 in the control group). The program was provided3 times a week for 8 weeks, 24 sessions each lasting 45~60 minutes. Effects of this program were evaluatedusing BMI, K-POMS-B, PANSS. The data were analyzed using percentage, x2-test, Kolmogorov-Smirnov test,paired t-test, t-test, and ANCOVA with SPSS 12.0 version. Results: After the aerobic exercise program, statisticallysignificant decreases in BMI, depression, fatigue score of the K-POMS, and psychiatric symptoms were foundfor the experimental group. Conclusion: These findings suggest that aerobic exercise programs are an effectivepsychiatric nursing intervention to decrease BMI, general psychiatric symptoms and fatigue, and also to improvemood states. Therefore aerobic exercise program are suggested as a potential approach for reducing re-hospitalizationand facilitating social readjustment for patients with schizophrenia.