Chemsex, the use of drugs during and/or prior to sex, has been found to increase the risk of HIV and sexually transmitted infections (STI) among men who have sex with men (MSM). Many studies and reviews on chemsex were focused among MSM in high-income countries (HIC), with less attention given to understanding chemsex in low- and middle-income countries (LMIC). We estimated the prevalence of chemsex and its association with sexual risk behaviors, HIV, and STI among MSM in LMIC. We searched MEDLINE, Embase, GlobalHealth, PsychINFO, and CINAHL for quantitative, qualitative, and mixed-methods studies describing chemsex and its association with sexual risk behaviors, HIV, and STI among MSM in LMIC, published January 1, 2000-October 15, 2023. We used the Mixed Methods Appraisal Tool to assess study quality. We developed a narrative review and performed meta-analysis using a random effects model and the DerSimonian and Laird approach (PROSPERO #CRD42022339663). Thirty-two studies from LMIC, particularly from Asia, Africa, Latin America, and the Middle East, were included. MSM who engaged in chemsex had higher prevalence of condomless anal intercourse, group sex, having multiple sexual partners, and of HIV and STI compared to MSM who did not. We estimated a pooled prevalence for recent chemsex (≤ 12 months) of 16% (95% CI 11%-22%, τ = 0.01, I = 99.07%, p < 0.01). Chemsex and its associated behaviors are associated with HIV and STI among MSM in LMIC. Integration of harm reduction and sexual health services and structural changes could prevent HIV and STI prevention among MSM who engage in chemsex in LMIC.