New and returning adult exercisers were tracked to evaluate the effect of a multiple component, behavior change treatment "package" on exercise attendance and drop out, within fitness facility settings in the United States, United Kingdom, and Italy. After assessing treatment participants' propensity for early drop out, various behavioral and cognitive behavioral treatments (e.g., goal setting, relapse prevention, self-reinforcement, contracting), exercise plans tailored to produce desirable affective change, and social support recruitment methods were administered by exercise leaders. Control group participants received typical exercise counseling that centered around amounts, types, and physiological results. Exercise leader-participant contact time over the 36- week studies were matched across treatment and control groups. Results of all 3 studies demonstrated significantly (p <.05) higher attendance (13-30%) and less drop out (30-39%) for the treatment groups, compared to their respective controls. Discussion included future possibilities for the use of behavior change treatments for supporting ongoing exercise and promoting positive physiological and emotional well-being. © 2003 by Human Kinetics Publishers and the European College of Sport Science.