Introduction. The burden of severe acute malnutrition (SAM) remains unacceptably high worldwide. The burden of Tuberculosis (TB) co-occurring with SAM in under 5 children is a significant focus for the improvement of child health. The co-existence of these diseases are significantly enhancing the associated morbidity, mortality, and hospitalization costs among this population. Objective. To determine survival status and predictors of TB development in under 5 children with SAM in Asella Referral and Teaching Hospital, Ethiopia. Methods. A retrospective cohort study was done in 247 under 5 children with SAM between January 01/2018 and December 31/2022. Systematic sampling technique was used to select the study participants. Data extraction format was used to collect data from the patient’s medical chart. EpiData version 4.6.0.6 was used for data entry and exported to STATA version 14.2 for statistical analysis. Result. This study includes 247 under 5 children with SAM with a response rate of 100%. Regarding to the survival status; 24(17%) of under 5 children with SAM have developed the events (TB) and the rest of them, 205(83%) were censored. The incidence density rate (IDR) of TB in under 5 children with SAM was 45.51 per 100 (95% CI: 33.63, 61.58) children-months observation. The cumulative incidence of TB was 17% (95% CI: 12.79, 22.25). Multivariable Cox proportional hazard analysis revealed that: having a history of TB contact (AHR = 5.56, 95% CI: 2.77, 11.15, P-value = .000), having a history of bottle feeding (AHR = 4.95, 95%CI: 1.08, 22.77, P-value = .040), did not take F100 (AHR = 1.71, 95% CI: 1.12, 7.25, P-value = .00) were statistically significant predictors of TB development. Conclusion. This study shows that the IDR of TB was high. Having a history of TB contact, history of bottle feeding, and not taking F100 were significant predictors of TB development. It is vital to address these predictors to prevent the development of TB in this population. Moreover, early screening of TB in these children should get high emphasize.