OBJECTIVES: Poor adherence to HIV antiretroviral therapies (ART) increases the risk of incomplete viral suppression, development of viral resistance, progression to acquired immune deficiency syndrome, and death. However, there is little understanding of the impact of specific treatment-related adverse events (AEs) on adherence. This meta-analysis was conducted to assess the effects of treatment-related AEs on adherence to ART in adult HIV-infected patients. METHODS: A systematic review of studies involving HIV-infected patients aged ≥16 years and reporting an odds ratio (OR) for factors affecting adherence to ART was conducted. Embase and MEDLINE databases were searched between 1996 and 2010. Bibliographies of identified review papers were also searched. Studies conducted in populations limited to a particular demographic characteristic or behavioral risk factor were excluded. To qualify for inclusion into the meta-analysis, treatment-related AEs had to be defined similarly across studies. Multiple ORs from the same study were included where study sub-groups were distinct. Random effects models were used to pool ORs.  RESULTS: Nineteen studies and 18 ART-related AEs were included in the analysis. Adherence to ART was significantly lower in patients with non-specific AEs than in patients who did not experience any AEs (OR=0.62; 95% CI: 0.46-0.83). Patients with specific AEs such as cough (OR=0.65; 0.53-0.79), fatigue (OR=0.63; 0.43-0.92), confusion (OR=0.35; 0.18-0.66), anxiety (OR=0.63; 0.41-0.95), taste disturbances (OR=0.49; 0.30-0.77), nausea (OR=0.57; 0.43-0.77), and loss of appetite (OR=0.54; 0.32-0.93) were significantly less likely to adhere to ART compared to patients without these AEs. Diarrhea, insomnia, sexual dysfunction, lipodystrophy, numbness, pain when swallowing, tingling in mouth/tongue, dermatological conditions, abdominal pain, and vomiting were not significantly associated with adherence, although trends toward decreased adherence were observed. CONCLUSIONS: Specific treatment-related AEs can significantly decrease adherence to ART. Knowledge of these effects may allow for targeted management of AEs to improve ART adherence and clinical outcomes.