Protective Factors have the potential to usefully complement dynamic risk factors in the development of effective clinical services for sexual offenders The theoretical and clinical value of this construct is presently handicapped by insufficient analysis of how a protective effect is achieved and by an implicit assumption that protective operate in the same way for all clients The first issue is examined by analyzing protective factors using Thornton (2016)’s expansion of the propensities model of risk. The second issue is addressed by contrasting the operation of protective factors for mainstream sexual offenders vs. individual for whom problematic sexual behavior and major mental illness co-occur This allows a range of protective processes to be enumerated and “protective factors” emerge as arena within which these processes can operate To effectively analyze protective factors this two-tier analysis has to be supplemented by a third tier which specifies the need and responsivity profile of the individual