Mycobacterium tuberculosis complex has an impact on public health and is responsible for over one million deaths per year. Substantial numbers of people infected with M. tuberculosis can develop tuberculosis lymphadenitis; however, there is a limited study in Adama, Ethiopia. The aim of this study was to determine the magnitude of Tuberculosis lymphadenitis, its predictors, and rifampicin-resistance gene-positive M. tuberculosis. A total of 291 patients with enlarged lymph nodes were recruited from May 2022 to August 30 at Adama Comprehensive Specialized Hospital Medical College (ACSHMC). GeneXpert, Ziehl-Neelsen staining, and cytology were used for the diagnosis of TB lymphadenitis from the Fine Needle Aspirate (FNA) specimen. Rifampicin-resistant gene was detected using GeneXpert. For data entry and analysis, Epi Data version 3.0 and SPSS version 25 were used respectively. A binary logistic regression model was used to identify predictors of TB lymphadenitis. A p < 0.05 with a 95% confidence interval (CI) was taken as a cut point to determine the significant association between dependent and independent variables. The prevalence of TB lymphadenitis using GeneXpert, Ziehl-Neelsen staining, and cytology were 138 (47.4%) (95% CI 41.70-53.10), 100 (34.4%) (95% CI 28.94-39.85), and 123 (42.3%) (95% CI 36.63-47.00) respectively. Nine (3.1%) participants were infected with rifampicin-resistant gene-positive M. tuberculosis. Out of the total M. tuberculosis detected by GeneXpert (n = 138), 9 (6.5%) were positive for rifampicin resistance-gene. Participants with a chronic cough had 2 times odds of developing TB lymphadenitis (AOR: 2.001, 95% CI 1.142-3.508). Close to half of patients with enlarged lymph nodes were positive for M. tuberculosis by the GeneXpert method in the study area. Chronic cough was significantly associated with TB lymphadenitis. Rifampicin-resistant gene-positive M. tuberculosis was relatively prevalent among patients with enlarged lymph node in the study area.© 2023. Springer Nature Limited.