Background: Despite the availability of effective drugs, tuberculosis remains a major public health problem that predominantly affects low-and middle-income countries. This study aimed to assess tuberculosis treatment outcomes among patients treated at one of the primary health care levels in Addis Ababa, Ethiopia. Methods: An institutional-based retrospective cross-sectional study was conducted at a tuberculosis clinic in public primary healthcare facility. The study populations were all patients with tuberculosis who had been completed their treatment course in the center from July 2014 to July 2018. After getting Ethical clearance and permission from the health center, trained data collectors working in the center were recruited. The collected data were checked for completeness every day by the principal investigators. Data were edited, cleaned, and analyzed using SPSS version 25. Descriptive statistics were used to summarize the data while multinomial logistic regression was employed to explore associations among variables of interest, and p < 0.05 was considered as statistically significant. Results: A total of 352 patients with tuberculosis were included for the study with a median age of 25 years which ranged from 1 to79 year. Most (36.4%) participants were in the age group of 15 to 24 years. The majority (38.8%) of patients had extrapulmonary tuberculosis, 11.9% of them were HIV positive and only two had family history of tuberculosis. Regarding treatment outcome, 238(67.6%) completed the treatment, 95(27%) cured and the rest were unsuccessful treatment outcomes 19(5.4%) either died, defaulted or treatment failed. The odds ratio for cured in relation to unsuccessful treatment outcome was found to be significantly higher in HIV negative patients (AOR = 6.1; 95%CI 2.1-13.9) compared with those patients tested positive for HIV. While patients with smearpositive pulmonary tuberculosis (AOR = 10.5, 95% CI 5.36-16.31) were significantly associated with the odds of having complete treatment cure as compared to patients with extrapulmonary tuberculosis. Similarly being HIV positive and extrapulmonary tuberculosis were predicting factors for unsuccessful treatment compared with their counterparts. Conclusions: The finding of the present study showed that successful tuberculosis treatment outcome was found to be optimal.