Sexual offender treatment programmes are often facilitated in secure settings such as prisons or psychiatric hospitals, which are not ideal environments for such treatment. Arguably, however, when these environments are structured as therapeutic communities (TCs), opportunities are created to enhance the effectiveness of treatment. This article describes the concept of a TC, its operating principles and rationale, as well as the benefits and rationale for establishing TCs in conjunction with cognitive-behavioural treatment with sexual offenders. This is discussed in terms of the potential of TCs to improve targeting of treatment content, to enhance treatment process, to provide optimal environments for therapeutic gain, and to provide a broad therapeutic framework for treating sexual offenders. The article reviews and summarizes what evidence exists for the use of TCs with both non-sexual offenders and sexual offenders. Finally, it highlights the gaps in our knowledge of the use of TCs to inspire further empirical and conceptual consideration of these issues.