We have used polymerase chain reaction (PCR) with IS6110 and a new set of primers from an insertion element like repetitive sequence, (TRC4) to detect Mycobacterium tuberculosis in pleural effusion samples from 50 patients having pleuritis. The results of PCR were compared with the results of conventional methods like smear, culture and adenosine deaminase activity. Thirty six specimens were positive and 14 were negative by PCR. Among the 36 samples, 33 were from patients with clinical evidence of tuberculosis including response to anti-tuberculosis therapy. Only six samples were positive by the gold standard which is culture, and three were positive by smear. The measurement of adenosine deaminase activity classified 19 samples as positives. The overall sensitivity and specificity of PCR was 100 and 85 per cent respectively. PCR using IS6110 and TRC4 primers is a sensitive test as compared to conventional tests for detection of M. tuberculosis from pleural fluid samples of patients with tubercular pleuritis.