Purpose: The purpose of this study was to identify correlation between sexual autonomy and self-efficacy and provide preliminary information for use in development of a sex education program for university students. Method: This study employed a descriptive research design. Data were collected from 357 university students. Subjects completed questionnaires on the following: demographics, sexual autonomy, and self-efficacy. Results: A total of 112 subjects (31.3.%) had experienced sexual intercourse and 126 subjects (35.3%) regarded it as an acceptable level of sexual behavior. The mean of sexual autonomy was 3.49 and significant differences were observed in gender, grade, department, and acceptable level of sexual behavior. The mean of self-efficacy was 4.08 and significant differences were observed in gender, department, and acceptable level of sexual behavior. In addition, significant correlation was observed between sexual autonomy and self-efficacy. Conclusion: Development of a sex education program for university students, which includes information on reinforcement of sexual autonomy and self-efficacy, is needed.