Introduction: Opportunistic infections (OIs) are the leading cause of morbidity and mortality among adults living with HIV. Current and accurate information about the occurrence of opportunistic infections in HIV-infected adults is critical for developing more effective treatments and interventions. However, few studies have been conducted in Ethiopia on the prevalence of common opportunistic infections in HIV-infected adults. Thus, the purpose of this study was to determine the prevalence and predictors of opportunistic infections among HIV-infected adults receiving antiretroviral therapy (ART) at the comprehensive specialized hospital affiliated with the University of Gondar. 
Methods: Between January 11, 2015, and January 10, 2021, a retrospective cohort study was conducted at the University of Gondar comprehensive specialized hospital. A total of 715 HIV-infected adults on ART were included in the study. Data were extracted from the charts of HIV-infected adults using a data extraction form adapted from the ART entry and follow-up forms. Epi-dataTM Version 4.5 was used to enter data, and StataTM Version 16 was used to analyze the data. The time interval between opportunistic infections was estimated using the Kaplan Meier survival curve. To identify risk predictors of opportunistic infections, bivariate and multivariate semi-parametric and parametric regression models were fitted.

Result: This study included the records of 715 HIV-infected adults-initiated ART between January 11, 2015, to January 10, 2021. During the follow-up period, the overall incidence of opportunistic infections was 4.1 (95 percent CI 3.74 to 4.44) per 10,000 person-year observation, with a median of 57 months (IQR=40-69 months).Pneumocystis’ pneumonia at 90(16.51%) was the most encountered OI at follow-up. Adults are presenting with baseline CD4