ABSTRACT: The purpose of the study was done to observe correlation of AFB, Monteux test and PCR in nontuberculosis mycobacterium for the detection and identification of clinically most frequent NTM at the species. A Prospective Experimental Study was done on 50 IP and OP patients for duration of 12 months who presented to various Departments of VMMC, Karaikal with signs and symptoms of Tuberculosis. Patients of All Age Group with clinical suspicion of Tuberculosis, Both New and Retreatment Tuberculosis Patients were included in the study. Microbiologically confirmed case of Mycobacterium Tuberculosis were excluded from the study. Out of 50 (100%) cases who took part in the study, sample type was distributed among 49 (98.0%) sputum samples and 1 (2.0%) bronchial wash. Out of 50 (100%) cases who took part in the study to determine the prevalence of Acid-Fast Bacilli (AFB), 24 (48.0%) of cases had Acid-Fast Bacilli and 26 (52.0%) had no Acid-Fast Bacilli in staining. Out of 50 (100%) cases who took part in the study to determine the prevalence of tuberculosis by MANTOUX screening, 37 (74.0%) tested positive for MANTOUX and 13 (26.0%) tested negative for MANTOUX. Out of 50 (100%) cases who took part in the study to determine the detection of genes by Polymerase Chain Reaction (PCR) test, 36 (72.0%) of cases had specific genes and 14 (28.0%) of cases had no specific genes detected by polymerase chain reaction. Out of 50 (100%) cases who took part in the study to determine the prevalence of Acid-Fast Bacilli and its gene by Polymerase Chain Reaction, 6 (42.9%) and 20 (55.6%) cases tested negative for acid-fast bacilli staining, 8 (57.1%) and 16 (44.4%) cases tested positive for acid-fast bacilli staining. For gene detection by polymerase chain reaction 6 (42.9%) and 8 (57.1%) cases had no specific genes where 20 (55.6%) and 16 (44.4%) of cases had specific genes. Out of 50 (100%) cases who took part in the study to the determine the prevalence of MANTOUX and its gene by Polymerase Chain Reaction prevalence, 2 (14.3%) and 11 (30.6%) of cases tested negative for MANTOUX test whereas 12 (85.7%) and 25 (69.4%) of cases tested positive for MANTOUX test. For specific gene detection by polymerase chain reaction 2 (14.3%) and 12 (85.7%) of cases had no specific genes but 11 (30.6%) and 25 (69.4%) of cases had specific genes suggesting that PCR is a technique of convenience.