Objective: to synthesize the knowledge and to critically evaluate the evidences arising from randomized controlled trials on the efficacy of the complementary therapies in the management of cancer pain in adult patients with cancer in palliative care. Method: a systematic review guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The search for articles in the MEDLINE, ISI Web of Knowledge, CENTRAL Cochrane, and PsycINFO databases, as well as the manual search, selection of studies, data extraction, and methodological assessment using the Cochrane Bias Risk tool were performed independently by two reviewers. Results: eight hundred and fifteen (815) studies were identified, six of them being selected and analyzed, of which three used massage therapy, one study used a combination of progressive muscle relaxation and guided imaging, and another two studies used acupuncture. Most of the studies had an uncertain risk of bias (n=4; 67%). Conclusion: while the evidence from the studies evaluating the use of massage therapy or the use of progressive muscle relaxation and guided imaging for the management of cancer pain in these patients demonstrated significant benefits, the other two studies that evaluated the use of acupuncture as a complementary therapy showed contradictory results, therefore, needing more research studies to elucidate such findings.