AbstractPurposeTo assess the effectiveness and safety of acupuncture for the prevention of chemotherapy‐induced nausea and vomiting (CINV), with a specific intention on exploring sources of between‐study variation in treatment effects.MethodsMEDLINE, EMBASE, Cochrane CENTRAL, CINAHL, Chinese Biomedical Literature Database, VIP Chinese Science and Technology Periodicals Database, China National Knowledge Infrastructure, and Wanfang were searched to identify randomized controlled trials (RCTs) that compared acupuncture to sham acupuncture or usual care (UC). The main outcome is complete control (no vomiting episodes and/or no more than mild nausea) of CINV. GRADE approach was used to rate the certainty of evidence.ResultsThirty‐eight RCTs with a total of 2503 patients were evaluated. Acupuncture in addition to UC may increase the complete control of acute vomiting (RR, 1.13; 95% CI, 1.02 to 1.25; 10 studies) and delayed vomiting (RR, 1.47; 95% CI, 1.07 to 2.00; 10 studies) when compared with UC only. No effects were found for all other review outcomes. The certainty of evidence was generally low or very low. None of the predefined moderators changed the overall findings, but in an exploratory moderator analysis we found that an adequate reporting of planned rescue antiemetics might decrease the effect size of complete control of acute vomiting (p= 0.035).ConclusionAcupuncture in addition to usual care may increase the complete control of chemotherapy‐induced acute vomiting and delayed vomiting but the certainty of evidence was very low. Well‐designed RCTs with larger sample sizes, standardized treatment regimens, and core outcome measures are needed.