Background: Evaluation of treatment success of tuberculosis treatment is used as a major indicator of program quality. However, treatment outcome of tuberculosis patients has not consistently been evaluated yet in private health facilities working with the public health facilities in tuberculosis diagnosis and treatment (PPM-DOTS) facilities. The objective of the study was to assess treatment success and associated factors among tuberculosis patients treated with Rifampicin based anti-TB in PPM-DOTS facilities in Oromia region, Ethiopia. Methods: A cross sectional analysis with internal comparison was performed on TB patients enrolled in PPM-DOTS program in Oromia region from January 1, 2011 to December 30, 2013. Results: Out of 1036 randomly sampled new TB patients enrolled in the study, 55% were male and 61.4% were pulmonary tuberculosis. Successful treatment outcome for all types of tuberculosis cases was observed in 890 (84.9%). Significant predictors of treatment success was follow-up sputum smear conversion at second month and type of PPM-DOTS facility. The odds of TB treatment success was reduced by 86% among TB patients whose second month sputum smear not converted at second month (AOR= 0.14, 95%CI: 0.05-0.48) compared to smear negative TB patients. Compared to TB patients treated in workplace health facility, TB patients who were treated in clinics had a 3.85 (95%CI: 1.25- 9.72) times higher chance of TB treatment success. Conclusion: The TB treatment success rate in PPM-DOTS facilities in Oromia region was high. Having follow-up sputum smear result negative at second month and being treated in higher clinic were found to be positive predictors of TB treatment success. Expanding PPM-DOTS facilities contribute a lot in achieving the national TB control program target.

Keywords: Treatment success, Tuberculosis, private health facilities, Oromia, Ethiopia