BackgroundTuberculosis remains to be a major public health problem among under developed world due to delay in detection and treatment of patients with active TB. In Ethiopia, tuberculosis has been recognized as a major public health problem for more than fifty years.ObjectiveThe main objective of this study was to determine treatment outcomes and associated factors among TB patients attending Nigist Eleni Mohammed General Hospital, Hosanna, SNNPR, Ethiopia.MethodsA five years medical records on treatment outcomes of tuberculosis was reviewed by using a retrospective study design. A total of 768 tuberculosis patients’ cards registered in TB unit register from June 2009 to August 2014 were reviewed. Data was coded, cleaned and entered into a computer data base by using EPI Info version 3.5.3 and then analysed by using Spss version 20.0 Descriptive summary values such as frequency and percentage was used to describe the study variable. Moreover, bivariate and multivariate logistic regression analysis with a confidence level of 95% was performed in order to determine the final predictors of the outcome variable. Association of age, sex, residence, HIV status of the patient and TB type/category was assessed with the TB treatment outcome through bivariate analysis. And residence, TB category and HIV status were found significantly associated with the treatment outcomes in bivariate analysis. Finally, the forward addition model was used for the multivariate analysis, and residence, TB category and HIV status of TB patient were entered into the final model to obtain an adjusted odds ratio (AOR).ResultOut of 768 TB patients who were registered at the hospital during the study period, 249 (32.4%) completed the treatment, 84 (10.9%) cured, 11 (1.4%) defaulted, 397 (51.7%) were transferred out to other health facility, 23 (2.9%) died and 4 (0.5%) failed the treatment regimen. In this study, the overall treatment success of TB was 333 (43.3%) as compared to their counterparts, 435 (56.7%). Patients who presented pulmonary TB + ve were more likely to develop risk of poor treatment outcomes as compared to the patients with extra pulmonary TB and pulmonary TB-ve (AOR = 1.915,95% CI;1.213,3.028). The proportion of TB HIV co-infection was16.4%, and HIV + ve TB patients were more likely to develop risk of poor treatment outcomes as compared to their counterparts (AOR = 0.796, 95% CI;0.512,1.236).ConclusionFrom this study, it was generally observed that the rate of defaulting was very low in the hospital. On the other hand, it was observed that the rate of transfer out of patients from the hospital to other health care facilities was very high during the study period. Furthermore, it was observed that patients who came from urban area were less likely to develop risk of poor treatment outcomes as compared to patients who reside in the rural areas.