The effectiveness of Mental Health Review Tribunals in providing safeguards for patients to ensure their right to be free from unjustified detention or treatment has been subject to much criticism in the literature. This article systematically reviews studies on the decision-making of such tribunals in order to synthesize the literature thematically and subject it to an assessment of methodological rigour [Hawker, S., Payne, S., Kerr, C., Hardey, M., & Powell, J. (2002). Appraising the evidence: reviewing disparate data systematically. Qualitative Health Research, 12(9), 1284]. Of the 7,845 citations initially identified, 50 papers met the inclusion criteria. Although most studies were found to have satisfactory methodological rigour, our assessment revealed some issues related to ethics and bias, sampling procedures, and data collection and analysis processes. Eleven prevailing themes were identified that largely relate to the shortfalls of current tribunal systems. Suggested areas for practical improvement and further research were also given. The article concludes by suggesting how future studies could be developed to cover areas in need of further research and with greater methodological rigour.