BackgroundThe health sectors success has been determined by consistent and reasonably priced health commodities supply. Despite possible death from the disease, Tuberculosis (TB) can be prevented with early diagnosis and appropriate treatment for which enough, effective, and qualified medicines need to be available. However, studies revealed stock of anti-TB drugs in health facilities. Here we present the recent finding on determinants of stock out of Anti-TB drug at public health facilities of Addis Ababa.ObjectiveThis study aimed to identify determinants of stock outs of first line anti TB drugs at public health facilities under Addis Ababa City Administration Health Bureau.MethodMixed study design were employed. A total of 106 facilities were included in the sampling frame and data were collected from the study population such as drug store managers of health facilities providing TB treatment using semi structured questionnaire and through in-depth interview with Addis Ababa hubs of the Ethiopian Pharmaceuticals Supply Agency (EPSA), Addis Ababa City Administration Health Bureau and selected heads of pharmacy departments of health facilities from May 1–30, 2020 considering one year back retrospective data from March 20,2019 to March 20,2020. Structured record review of data from Logistics Management Information System (LMIS) tools having TB drugs was done using structured observation checklist. Data were entered, cleaned, and analyzed using SPSS Version 20. Both descriptive and multiple logistic regression analysis were performed.Result52(62.7%) of health facilities encountered stock out for at least one of these drugs during the past 1 year. Rifampicin 75 mg + Isoniazid 50 mg (RH 75/50 mg) were most stocked out first line anti-TB drug from 33(39.8%) of facilities with 17 mean stocks out days while Rifampicin 75 mg + Isoniazid 50 mg + Pyrazinamide 150 mg (RHZ 75/50/150 mg) were the least first line anti-TB drug stocked out from facilities with mean 5 days of stock out. Delayed supply of anti TB drug from EPSA, delivery of reduced quantity of anti TB drugs by EPSA and stocked out of anti TB Drugs at EPSA were significant determinate factors of stock out of first line anti-TB drug from facilities with 95%CI of 10.34(2.167–49.329), 11.452(2.183–60.079) and 5.646(1.240–25.707) respectively.ConclusionAbove median of health facilities encountered stock out of first line anti-TB drug in Addis Ababa. Delayed supply of anti TB drug from EPSA, delivery of reduced quantity of anti TB drugs by EPSA and stocked out of anti TB Drugs at EPSA were significant determinate factor of stocked out of first line anti-TB drug from facilities. EPSA and other responsible bodies shall work collaboratively to improve their service and ensure availability of adequate amount of Anti TB drug in health facilities.