Although it has been shown that participation in victim-offender mediation (VOM) can be associated with a lower risk of reoffending, it remains unclear how the VOM process may explain this relationship. Through a synthesis literature review, which included 53 articles, this article provides an overview of mechanisms in three phases of the VOM process that might contribute to a lower risk of reoffending. These are the preliminary phase (before the VOM encounter), the execution phase (VOM encounter) and the outcome phase (after VOM encounter). The findings of the review indicate that although a possible self-selection bias in the preliminary phase may (partly) account for the negative association with recidivism, multiple fundamental conditions and working mechanisms in the VOM process and encounter can help explain a psychological change within the offender and hence a lower recidivism risk. However, the review reveals remaining knowledge gaps regarding the contribution of VOM to reduced reoffending. To fill these gaps, we offer a number of recommendations for future research, such as examining how the fundamental conditions and working mechanisms of VOM interact with each other and produce a psychological change within the offender. This could help to find best practices that maximise the beneficial outcomes of VOM.