The objective of the review was to identify and assess the quality of studies of the costs and benefits of different sentencing options. The review found only nine studies providing costs and benefits information. Due to the small number of studies uncovered by the review and, in some cases, poor methodologies, it has not been possible to draw firm conclusions from the individual studies in order to make comparisons between studies on the benefit‐cost of particular sentencing options. Tentative conclusions are drawn, where supporting evidence is available, and the authors recommend improved quality of research design and the development of standardized methodologies for assessing the costs and benefits of criminal justice interventions. Abstract Introduction Sentencing policies are most frequently designed by policy‐makers and implemented by the courts with the aim of punishing, deterring and rehabilitating offenders in order to reduce future re‐offending. However many sentencing decisions are made without knowledge of the effectiveness of sentences in achieving their objectives, or the costs and benefits of the different sentencing alternatives. The following systematic review was conducted in order to address these questions and to review the existing evidence on the costs and benefits of different sentencing options. Results from cost‐effectiveness studies were retained to provide supporting information. Objective The objective of the review was to identify and assess the quality of studies of the costs and benefits of different sentencing options. Search Strategy Pre‐screening and hand‐searching of published and available unpublished literature was completed by two independent reviewers. The structured searches were carried out on studies published between 1980‐2001, using nine electronic databases and by consulting experts in the field. Selection Criteria Studies were included in the review if they contained information on the costs and benefits of sentencing options. Due to the small number of benefit‐cost studies found, cost‐effectiveness study outcomes were also retained. Data collection and analysis Results from nine benefit‐cost studies and eleven cost‐effectiveness studies are reported in narrative and tabular form. Benefit‐cost ratios are presented alongside benefit‐cost outcome measures. The quality of studies is reported using the Maryland Scientific Scale (Sherman, Farrington, Welsh & Mackenzie, 2002) and a Benefit‐Cost Validity Scale ‐ Revised (Cohen & McDougall, 2008, Appendix 1). Main results The review found only nine studies providing costs and benefits information. Six of these studies were assessed as providing a ‘valid’ or ‘comprehensive’ benefit‐cost analysis, acceptable on the Benefit‐Cost Validity Scale – Revised, covering a range of different sentences. Two studies of In‐prison Sex Offender Treatment were found to be cost‐beneficial, in addition to an Intensive Supervision program and a Youth Wilderness Program, though the two latter interventions are less well‐supported by the wider research evidence. Diversion from imprisonment to drug treatment was assessed by its authors to be cost‐beneficial; and imprisonment for high risk offenders was considered to be cost‐beneficial, though not for less prolific offenders or for drug offenders. The three studies which provided only a ‘partial’ benefit‐cost analysis examined effectiveness of probation vs. prison, prisoners released early compared to those serving a full term, and house arrest with electronic monitoring. Reviewer's comments Due to the small number of studies uncovered by the review and, in some cases, poor methodologies, it has not been possible to draw firm conclusions from the individual studies in order to make comparisons between studies on the benefit‐cost of particular sentencing options. Tentative conclusions are drawn, where supporting evidence is available, and the authors recommend improved quality of research design and the development of standardized methodologies for assessing the costs and benefits of criminal justice interventions.