BackgroundCardiovascular diseases (CVDs) have become an important cause of ill health and death among people living with HIV and/or AIDS (PLHIV) in the antiretroviral therapy (ART) era. There is scarce data on the burden of hypertension (HTN) and risk factors for CVDs among PLHIV in developing countries, including Tanzania during the ART era.Objective(s)To determine the prevalence of HTN and risk factors for CVDs among ART naïve PLHIV initiating ART.MethodsWe analysed baseline data of 430 clinical trial participants on the effect of low-dose aspirin on HIV disease progression among HIV-infected individuals initiating ART. HTN was the outcome CVD. Traditional risk factors for CVDs studied were age, alcohol consumption, cigarette smoking, individual and family history of CVDs, diabetes mellitus (DM), obesity/overweight, and dyslipidaemia. A generalized linear model (robust Poisson regression) was used to determine the predictors for HTN.ResultsThe median (IQR) age was 37 (28, 45) years. Females were the majority contributing 64.9% of all participants. The prevalence of HTN was 24.8%. The most prevalent risk factors for CVDs were dyslipidaemia (88.3%), alcohol consumption (49.3%), and overweight or obesity (29.1%). Being overweight or obese predicted the occurrence of HTN, aPR 1.60 (95% CI 1.16–2.21) while WHO HIV clinical stage 3 was protective against HTN, aPR 0.42(95% CI 0.18–0.97).ConclusionThe prevalence of HTN and traditional risk factors for CVDs in the treatment naïve PLHIV initiating ART are significant. Identifying these risk factors and managing them at the time of ART initiation may lower future CVDs among PLHIV.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12872-023-03332-6.