Purpose: The study was done to identify factors influencing the quality of life of people with mental disabilities who use mental health centers. Methods: Data were collected by questionnaires from 288 people with mental disabilities in Busan and Kyungnam Provience. Data were analyzed using t-test, ANOVA, Pearson correlation coefficients, multiple linear regression with the SPSS/WIN 14.0 program. Results: The mean score for quality of life was 11.3±1.70, and the mean empowerment score was 59.7±8.44. The significant factors influencing quality of life were gender, age, residential status, number of support people, side-effects of drugs, service type, and empowerment. These factors explained 43.9% of the variance. Conclusion: The results suggest that in development and practice of program to increase the quality of life of people with mental disabilities a variety of factors should be considered.