The correctional community has engaged in a surge of sex offender treatment programs, within both correctional institutions and communities. While there has been an increase in efforts to assess the effectiveness of these programs, the research has been hampered by inconsistency in appropriate outcome measures. The present study addresses these shortfalls, while focusing on the early behavioral lapse indicators. The study focuses on the premise that not all sex offenders lapse in similar manners, and that those with adult and statutory victims would show more impulsive-criminal trends in lapse behavior when compared to those with child victims. This study is a quasi-experiment since the independent variable (treatment) was administered prior to the onset of research, and the data was collected over a 2-yr time frame. Dependent variables were divided into the areas of substance usage, non-sexual criminal activity, failure to attend aftercare treatment, and deviant sexual behavior that was deemed not severe enough to warrant new sexual criminal charges. 77 sex offenders successfully completed the treatment. The results support the premise that the different categories of sex offenders relapse at different rates and manners on several variables, but not on sexual deviancy. (PsycINFO Database Record (c) 2016 APA, all rights reserved)