Schema Therapy is becoming an increasingly popular psychological model for working with individuals who have a variety of mental health and personality difficulties. The aim of this review is to look at the current evidence base for Schema Therapy and highlight directions for further research. A systematic search of the literature was conducted up until January 2011. All studies that had clinically tested the efficacy of Schema Therapy as described by Jeffrey Young (1994 and 2003) were considered. These studies underwent detailed quality assessments based on Scottish Intercollegiate Guidelines Network (SIGN-50) culminating in 12 studies being included in the review. The culminative message (both from the popularity of this model and the medium-to-large effect sizes) is of a theory that has already demonstrated clinically effective outcomes in a small number of studies and that would benefit from ongoing research and development with complex client groups. It is imperative that psychological practice be guided by high-quality research that demonstrates efficacious, evidence-based interventions. It is therefore recommended that researchers and clinicians working with Schema Therapy seek to build on these positive outcomes and further demonstrate the clinical effectiveness of this model through ongoing research.