Background: Perfectionism is implicated in a range of psychiatric disorders, impedes treatment and is associated with poorer treatment outcomes. Aims: The aim of this systematic review and meta-analysis was to summarize the existing evidence for psychological interventions targeting perfectionism in individuals with psychiatric disorders associated with perfectionism and/or elevated perfectionism. Method: Eight studies were identified and were analysed in meta-analyses. Meta-analyses were carried out for the Personal Standards and Concern over Mistakes subscales of the Frost Multi-Dimensional Perfectionism Scale (FMPS) and the Self Orientated Perfectionism and Socially Prescribed Perfectionism subscales of the Hewitt and Flett MPS (HMPS) in order to investigate change between pre and postintervention. Results: Large pooled effect sizes were found for the Personal Standards and Concern over Mistakes subscales of the FMPS and the Self Orientated Perfectionism subscale of the HMPS, whilst a medium sized effect was found for change in Socially Prescribed Perfectionism. Medium pooled effect sizes were also found for symptoms of anxiety and depression. Conclusions: There is some support that it is possible to significantly reduce perfectionism in individuals with clinical disorders associated with perfectionism and/or clinical levels of perfectionism. There is also some evidence that such interventions are associated with decreases in anxiety, depression, eating disorder and obsessive compulsive symptoms. Further research is needed in order to investigate the optimal dosage and format of such interventions as well as into specific disorders where there is a lack of evidence for their effectiveness.