Treatment fidelity tools are frequently used in clinical trials, promoting treatment consistency and therefore validity of trial findings. However, treatment fidelity procedures have not been included within international clinical trial guidelines such as the Consolidated Standards of Reporting Trials (CONSORT 2010). Aim: This study systematically reviews psychological clinical trials that incorporate Treatment Fidelity procedures and appraises their implementation using the Implementation of Treatment Integrity Procedures Scale (ITIPS). Method: Using the PRISMA Checklist as a guide for systematic review, a comprehensive search of the Medline, PsychINFO, Ovid, Cochrane Library, Scopus, PUBMED databases for the period 2004 to 2014 resulted in retrieval of 3186 potential articles. Thirty-two studies meeting inclusion criteria were analysed against the ITIPS. Results: Sixteen studies were assessed as approaching adequacy in implementing Treatment Fidelity procedures as measured by the ITIPS scale, 8 studies were assessed as adequate whilst a further 8 studies were deemed inadequate against this assessment. Treatment Fidelity tools generally increased the intensity of the intervention or program within which they were used, resulting in improved levels of Treatment Fidelity. Conclusion: Current evidence supporting the inclusion of Treatment Fidelity tools is limited since there have been relatively few published studies examining the effectiveness of Treatment Fidelity tools. Further research into the efficacy, feasibility and measurement of Treatment Fidelity in implementing treatments is recommended, in tandem with additions to the CONSORT Guidelines to better support the inclusion of Treatment Fidelity procedures within clinical trials.