Diagnosis of extrapulmonary tuberculosis (EPTB) is difficult owing to low number of bacilli in the specimens, lack of adequate sample and non-uniform distribution of bacteria in tissues. The aim of this study was to investigate the utility of acid-fast bacilli (AFB) staining in biopsy specimens with typical granulomatous inflammation in patients with extrapulmonary tuberculosis and some related predictors.This study included 226 tissue biopsies of patients with EPTB showing typical granulomatous inflammation. Ziehl-Neelsen staining was performed for acid fast bacilli on paraffin embedded sections of tissue blocks. The most common site of involvement was pleura followed by vertebral and lymph nodes. Past history of pulmonary tuberculosis was positive in 46% of patients. The overall AFB positivity in specimens was 26.1%. The most positivity was in pleural TB (35.2%) and the least was in bone and joints TB (4.8%). There was significant association between site of involvement and AFB positivity (p=0.042). In multivariate logistic regression model, previous history of pulmonary tuberculosis was strongly associated with AFB positivity. Our study showed somewhat higher rate of smear positivity for acid fast bacilli in tissue specimen with typical pathology in some types of EPTB especially in patients with history of pulmonary tuberculosis. Despite low sensitivity, this method should be performed in patients suspected to EPTB especially in developing counties where new modality is not routinely available
