This study presents the findings of an evaluation of the Aggression Replacement Training programme as regards the reconviction of male violent offenders within the English and Welsh Probation Service. This study employed a quasi-experimental design which utilised one-to-one matching on key criminogenic variables between an experimental group and a comparison group. The experimental group comprised convicted violent offenders who had been allocated to the programme by probation staff, while the comparison group was sampled from a larger pool of individuals who had been convicted of a violent offence and had subsequently received a community sentence but were not allocated to the programme. Outcome data were analysed using both the ‘intention to treat’ and ‘treatment received’ methodologies. The latter methodology allowed comparison of the naturally occurring groups of completers and non-completers with their matched comparisons and each other. The phi effect size correlations indicated a 13.3% decrease in reconviction in the experimental group as compared to the matched comparison group. Additionally, programme non-completers were more likely to be reconvicted than their matched comparisons and programme completers. These findings are discussed in the light of the extant literature, and different interpretations are considered.