An experimental design was employed to assess the effectiveness of a relapse prevention program, a reinforcement program, and an exercise-only control group in increasing exercise program adherence and short-term maintenance in 120 previously sedentary female university employees. The subjects participated in an 18-week exercise program composed of stretching, calisthenics, and aerobic dance. Attendance during the first half of the program was significantly higher for subjects in the relapse prevention group than for those in the control group. A nonsignificant trend in this direction emerged during the second half of the program and at 2-month follow-up. For all treatment groups, attrition (attendance at less than two thirds of the exercise sessions) was substantial, averaging 72% at the end of the 18-week program. These findings indicate that relapse prevention and reinforcement programs may not assist previously sedentary females in long-term adherence to an exercise program.