Introduction: Reiki is an ancient form of Japanese healing. While this healing method is widely used for a variety of psychologic and physical symptoms, evidence of its effectiveness is scarce and conflicting. The purpose of this systematic review was to try to evaluate whether Reiki produces a significant treatment effect. Methods: Studies were identified using an electronic search of Medline, EMBASE, Cochrane Library, and Google Scholar. Quality of reporting was evaluated using a modified CONSORT Criteria for Herbal Interventions, while methodological quality was assessed using the Jadad Quality score. Data extraction: Two (2) researchers selected articles based on the following features: placebo or other adequate control, clinical investigation on humans, intervention using a Reiki practitioner, and published in English. They independently extracted data on study design, inclusion criteria, type of control, sample size, result, and nature of outcome measures. Results: The modified CONSORT Criteria indicated that all 12 trials meeting the inclusion criteria were lacking in at least one of the three key areas of randomization, blinding, and accountability of all patients, indicating a low quality of reporting. Nine (9) of the 12 trials detected a significant therapeutic effect of the Reiki intervention; however, using the Jadad Quality score, 11 of the 12 studies ranked "poor." Conclusions: The serious methodological and reporting limitations of limited existing Reiki studies preclude a definitive conclusion on its effectiveness. High-quality randomized controlled trials are needed to address the effectiveness of Reiki over placebo.