Background: Ethiopia introduced directly observed therapy short-course (DOTS) strategy for TB in 1995; reaching its full coverage in 2005. Treatment success rate (TSR) was 84% in 2009 and dropped to 83% in 2010. Despite the progress made in tuberculosis control throughout Ethiopia, risk factors leading to poor treatment outcome have not been assessed in Dessie and Woldiya town health institutions. Therefore, this study aimed to determine treatment outcome of TB patients and risk factors for poor treatment outcome in Dessie and Woldiya town health institutions, Northeast Ethiopia.