In contrast to the Martinson’s (1974) ‘Nothing works’ view, the ‘What works ?’ approach to correctional treatment has focused on whether correctional treatment can be effective in reducing offenders’ criminal recidivism. The empirical evidence reviewed in this paper supports that the Andrews and Bonta’s (2006) risk-need-responsivity principles provide the bases of an effective model of rehabilitation. Yet, despite great strides toward the development and implementation of evidence-based correctional treatment, there continues to be areas that require further development. In this paper, three issues frequently neglected in offender rehabilitation are additionally discussed, namely the need to attend to motivational issues among offenders, the importance of staff skills and attitude, and the need to continually document and evaluate rehabilitative practices.