Sudan, particularly the eastern part shoulders 8% of TB burden in the World Health Organization (WHO) Eastern Mediterranean Region (EMR). Kassala state is classified as one of the most tuberculosis (TB) affected states in Sudan with annual risk of around 120 new cases per 100,000 of populations. TB medications take a relatively long time to ensure adequate treatment. Default from TB treatment leads to continuation of disease transmission and multidrug resistant TB cases. Default rate in Kassala state is 11% while the globally acceptable rate is below 4%. This study aimed to find out the main risk factors associated with default from TB treatment among pulmonary TB patients in Kassala state in 2013. The study used case control design with (102 cases and 204 controls), structured questionnaire was used to collect socio-demographic factors. Multivariate logistic regression analysis model was built to quantify the association between risk factors and study outcome. Male to female ratio was 3:2, with age ranges between 15 and 85 years and the mean was 44 years ± 17.4 years. Stopping treatment after feeling improved and completing the intensive treatment phase was an important predictor of defaulting. Age and education level are found to be negatively associated with the default from the TB treatment. Stigma was also found to be strongly associated with the default rate. The current DOTS strategy and its components should be further strengthened by raising attention of medical personnel towards the strategy. An effective communication channel between the care provider and the patient should be mainlined to better education and ensuring of maximum adherence to treatment regimen.