Background: Hypertension is the major risk factor for cardiovascular diseases related morbidity and mortality. Blood pressure is often not adequately controlled in clinical practice. Information regarding blood pressure control in primary care settings is limited in Ethiopia. Objectives: This study aimed to assess blood pressure control practice and determinates among hypertensive patients attending primary health care facilities in Addis Ababa. Methods: A cross-sectional study was conducted on 616 hypertension patients in 12 health centers in Addis Ababa city. Data were collected by interviewing patients and reviewing their medical records. Data were collected from 3 August to 30 October 2015. Results: A complete information was obtained from 616 patients’ medical records, and patients were then interviewed. The mean age was 58.90 (SD ± 13.04) years, and most of them (n = 321, 52.1%) were 60 years old or above, and more than three-fourth (n = 485) were on monotherapy. Methyldopa was the most monotherapy medication prescribed, 128 (20.8%). Only 31% (n = 191) of the patients had controlled blood pressure. Determinants for poor blood pressure control were age less than 60 years (adjusted odds ratio (AOR) = 3.06, 95% confidence interval (CI): 1.96, 4.78); work status: government employee (AOR = 2.41, 95% CI: 1.18, 4.90), retired (AOR = 1.79, 95% CI: 1.01, 3.18), and private business (AOR = 2.09, 95% CI: 1.17, 3.74); and being hypertensive for 10 or more years (AOR = 1.96, 95% CI: 1.11, 3.43). Significant predictors of achieving controlled blood pressure were weekly blood pressure measurement practice (AOR = 0.57, 95% CI: 0.36, 0.90) and tertiary-level education (AOR = 0.26, 95% CI: 0.13, 0.54). Conclusions: Only one-third of the patients had controlled blood pressure. Efforts should be made to address identified determinants including age, regular blood pressure monitoring practice, and level of education.