To study the diagnostic accuracy of Acid fast bacilli smear with the gold standard TB culture by MGIT method. Materials and Methods: 547 patients were screened for tuberculosis based on criteria for Tuberculosis like cough for more than 2 weeks, fever, loss of weight and loss of appetite, haemoptysis. Observations& Results: Out 547 patients screened for tuberculosis, 237 patients were positive for tuberculosis by MGIT culture method and only 100 patients were positive by AFB smear method. The sensitivity was 42.19%, specificity was 99.03%, and the diagnostic accuracy was 74.41%. Conclusion: The sensitivity of acid fast bacilli smear is low with high specificity. There is a need for a inexpensive and better tool for rapid diagnosis of tuberculosis.