Background: After the introduction of Highly Active Anti Retro Viral Treatment (HAART), survival of people living with HIV/AIDS (PLHIV) has improved. However, other comorbid conditions like, hypertension are becoming a major challenge among PLHIV. Very little attempt has been made to investigate hypertension and contributing factors among clients receiving HAART particularly in southern Ethiopia. Objective: To determine the magnitude of hypertension and associated factors among clients receiving HAART at Wachemo University Nigist Elleni Mohammed Memorial Referral Hospital. (NEMMRH)- Hossana, Ethiopia, 2019/20. Methods and Materials: A Hospital based cross sectional study was conducted from January 20 to March 20, 2020 among HIV positive adults receiving HAART in NEMMRH. A systematic sampling was employed to select 397 clients. Interviewer administered pretested structured questionnaire was used for data collection. Blood pressure and anthropometric parameters of PLHIV were measured. Data were coded and entered using Epi Data Version 3.1 then exported to SPSS version 20 for analysis. Proportion, mean and standard deviation were used to describe the study variables. Then bivariable and multivariable logistic regression analyses were used to identify associated factors. Adjusted Odds Ratio (AOR) with 95% CI was used to present the estimated effect size and declare the presence of statistically significant association respectively. Result:. The magnitude of hypertension in the study setting was 11% .Being on HAART for >= 60 months [AOR, 2.57, 95% CI: [1.24, 5.23], being on TDF/3TC/EFV combination [AOR, 13, 95% CI: [3.54, 48.3], being on TDF/3TC/NVP combination [AOR, 5.36, 95% CI: [1.71, 16.8] and high alcohol drinking [AOR ,4.3, 95% CI: [1.84, 10.25] were independent factors found to have association with hypertension among clients receiving HAART. Conclusion and Recommendation: The magnitude of hypertension in the study setting was in a considerable state to plan and implement intervention measures. A due emphasis on planning intervention measures to reduce hypertension among clients who were on TDF/3TC/EFV& TDF/3TC/NVP combinations, for clients who were on HAART for >= 60 months and designing intervention strategies to reduce high alcohol drinking among PLWHA are pivotal and needs to be done for reversing the occurrence of hypertension in the study setting.