IntroductionIt is well established that starting antiretroviral therapy (ART) increases a patient's life expectancy among HIV-positive individuals. Considering the HIV pandemic, the major concern is initiation of ARTs to the large segment of HIV infected population, not adverse events from immune restoration. The prevalence of HIV-associated immune reconstitution inflammatory syndrome (IRIS) is poorly estimated due to Africa's underdeveloped infrastructure, particularly in Eastern Africa. Therefore, this study compiled data regarding the magnitude and associated factors of IRIS in the context of Eastern Africa.MethodsThe electronic databases such as Google Scholar, PubMed, Web of Science, and free Google access were searched till 5 June 2021, and the search was lastly updated on 30 June 2022 for studies of interest. The pooled prevalence, and associated factors with a 95% confidence interval were estimated using the random effects model. The I2 and Egger's tests were used for heterogeneity and publication bias assessment, respectively.ResultsThe development of HIV-associated IRIS in Eastern Africa was estimated to be 18.18% (95% CI 13.30–23.06) in the current review. The two most common predictors of IRIS associated with Eastern Africa were the lower pre-ART CD4 T-cell count of 50 cells/μl and the low baseline body mass index level. Therefore, attention should be focused on the early detection and care of HIV-associated IRIS to reduce the morbidity and death caused by IRIS.