Background: Tuberculosis (TB) was one of the top 10 causes of death worldwide in 2018. It isrnalso the leading killer of people with HIV and a major cause of deaths related to antimicrobialrnresistance. Ethiopia is among the 30 high burden tuberculosis countries, with annual estimatedrnTB incidence of 151/100,000 population and HIV negative TB mortality of 22/100,000 populationrnas of 2018 global TB report. At present, the major problem in managing TB is lack of an accuraternand rapid diagnostic test. Accordingly, rapid diagnostic test for detection of TB and rifampicinrnresistance currently available is the GeneXpert assay as WHO recommended. However healthrnfacilities which having GeneXpert diagnostic device encountered different challenges duringrnimplementation.rnObjective: This study was aim to assess the reasons for service interruption and Unsuccessful testrnresults related to GeneXpert diagnostic service in Addis Ababa public health facilities. rnMethods: Cross sectional study design was conducted in public health facilities which providedrnGeneXpert diagnostic service in Addis Ababa, Ethiopia. Quantitative and qualitativernquestionnaires based data was collected from January to March 2020. The data was cleaned,rnentered and analyzed using SPSS version 20 at a statistical significance of P value â‰¤ 0.05 usingrnlogistic regression. While the qualitative data obtained was summarized in thematic narrativernform.rnResults: Reasons of GeneXpert diagnostic services resulted to service interruptions andrnunsuccessful test results identified in this study. At least once or more than one times of servicerninterruption of GeneXpert were occurred in 82% of the health facilities in the study period. Servicerninterruption were dependent on the stock out of cartridge (rnX2 rn=10.6, p value