Drug misuse among people living with HIV (human immunodeficiency virus) is associated with higher mortality. It is a frequently observed reason for treatment abandonment, with people who misuse drugs showing a 10 to 25 times higher risk of HIV than the general population. The authors conducted a systematic review and meta-analysis to assess the efficacy of contingency management (CM) to improve adherence to antiretroviral therapy in people living with HIV and substance use disorder (SUD). The inclusion criteria consisted of studies written in English, Italian, Spanish, German, and French; studies conducted with humans; and clinical trials that combined SUD treatment with CM for people living with HIV. Two hundred twenty-two articles were identified, five met all inclusion criteria, and three provided enough data to perform the meta-analysis. We considered treatment adherence by measuring the increase in the CD4 count as our primary outcome. We found a significant increase in treatment adherence in the patient group compared with the control groups during the intervention phase. Positive findings did not persist after the cessation of the incentives. The meta-analysis showed that the intervention improved patient adherence by 2.69 (95% confidence interval: [0.08, 0.51]; p = 0.007) compared with the control group during the intervention period. All short-term CM studies converged on a positive result for adherence to antiretroviral therapy.