The current paper critically reviews the Risk-Need-Responsivity (RNR) and Good Lives Model (GLM) approaches to correctional treatment. Research, or the lack thereof, is discussed in terms of whether there is a need for a new model of offender rehabilitation. We argue that although there is a wealth of research in support of RNR approaches, there is presently very little available research demonstrating the efficacy of the GLM in terms of the impact that programs based on this model of rehabilitation have on observed rates of recidivism among offender populations. Additionally, the emphasis of the GLM approach on the principles and techniques of positive psychology is untested in the area of forensic psychology. Evidence with reference to the assessment and treatment of sexual offenders is discussed as this is a particular focus of the GLM approach. We conclude, in agreement with the developers of the GLM approach, that the RNR model needs to be adapted in order to incorporate recent research related to the factors associated with recidivism among sexual offenders. However, we argue that the GLM is largely an empirically untested model, and further offers little in terms of adding to or replacing the RNR model. We recognize that a revised version of the RNR based approach is necessary, incorporating an integrated approach to treatment, and we introduce and briefly describe the RNR-I (Integrated)), a model developed by the authors and supported by a variety of empirical research, including a number of outcome studies produced by our team and others.