Background: The majority of hypertension people are at high risk of developing cardiovascular disease.rnThe primary barriers to controlling hypertension are a lack of awareness about the disease and poorrnmedication adherence, both of which have a negative influence on the patient's behavior. rnObjective: To assess knowledge of hypertension and compliance of treatment and factors associatedrnamong hypertension patients at TASH Addis Ababa Ethiopia, 2021. rnMethods: The institutional based cross sectional study design was used at TASH, and 375 hypertensivernpatients were recruited in the follow-up clinic. The data was gathered using a standard structuredrnquestionnaire. Face-to-face interviews were used to conduct a survey by professional data collectors. EPIdatarnrnwas used to enter data, which was then exported to statistical package for social science(SPSS)rnsoftware version 20 for additional analysis. Multiple linear regression and binary logistic regressionrnanalysis were employed to assesâ€™ factor associated with knowledge and association between compliancernand indpendnet variables respectively. The association between variables was determined by the p valuesrnbelow 0.05 using 95% confidence level (CI). rnResult: The current study found that only 45.9% of patients comply with antihypertensive therapy andrnmajority of the respondets (63.75%) have good knowledge about hypertension except only around onethirdrnrn(35.4%) were aware of the signs and symptoms of hypertension. Factors that associated withrntreatment compliance were including: Age above 60 years(AOR=0.129; 95% CI: 0.066,0.254), no formalrneducation ( AOR=0.250; 95% CI: 0.099, 0.634), less than 5 years since hypertension diagnosisrn(AOR=3.989; 95% CI: 1.586,10.033)., comorbidity(AOR= 0.360; 95% CI: 0.195,0.665), and missingrnmedications (AOR= 0.366 ; 95% CI: 0.199, 0.674) were associated with poor treatment compliance,rnwhereas rigorous physical activity(AOR=1.169; 95% CI: 1.003,1.362); and client knowledge ofrnhypertension(AOR=1.336; 95%CI: 1.106, 1.615) . In addition, the factors associated with knowledge ofrnHTN include, no formal education Î²=-0.815;(-1.293, -0.337) and governmental employment Î²=1.164;rn(0.626,1.702), were found to be statistatically significant association with knowledge of HTN. rnConclution and recommendation: The current study reveled that only 45.9% of partisipants complyrnwith antihypertensive terapy and more than one third of the participant were aware of the signe andrnsymptoms of HTN. Therefore, the findings suggest that health care practitioners should pay attention tornincrease the awareness of clinets toward antihypertensive treatmet adherence in order to minimize therncomplications.