Dereje N, et al. - Pre-ART and On-ART HIV-infected patients were examined for the prevalence and predictors of opportunistic infections. In this comparative cross-sectional study, researchers categorized patients who were infected with HIV, but not eligible for ART as Pre-ART follow-up group (n = 192) and those patients who started taking ART as the On-ART follow-up group (n = 192). Opportunistic infections were prevalent in 33.6% (95% CI; 28.9–38.5) participants. The Pre-ART group (38%) had higher prevalence of opportunistic infections than On-ART group (29.2%). In both Pre-ART and On-ART groups, the most common opportunistic infection was pulmonary tuberculosis. Independent predictors for the development of opportunistic infections were being in the WHO clinical Stage III (AOR = 2.1; 95% CI 1.1–3.9) or Stage IV (AOR = 3.6; 95% CI 1.7–7.7). Findings emphasize early initiating ART among HIV-infected patients irrespective of their CD4 counts.