Purpose: The purpose of this study was to examine the effect of the Tai chi exercise program on the physical function, self-esteem and social behavior in patients with chronic schizophrenia. Methods: This study utilized a nonequivalent control group with pretest-posttest design. The 45 subjects were recruited from a mental health care facility in D city and randomly assigned either to the experimental group (n=23) or to the control group (n=22). The experimental group participated in the Tai chi exercise program, twice a week for 12 weeks. Data were analyzed with SPSSWIN V. 11.5 program, using $X^2$-test and t-test. Results: After 12 weeks, there were significant differences in flexibility (p=.027), balance (p=.011), self-esteem (p=.005) and social behavior (p=.003) between the experimental and the control groups. Conclusion: The findings of this study revealed the positive effects of Tai-Chi exercise program in patients with schizophrenia. Further studies are required to determine the effects on physical and social variables.