Laboratory methods play a crucial role in establishing the diagnosis, monitoring the therapy, preventing the transmission of extra pulmonary tuberculosis. Conventional methods like smear and culture are either less sensitive or time consuming. Newer diagnostic tools such as BacT/Alert and Polymerase chain reaction takes less time with high sensitivity. However, both false negative and false positive results are reported on PCR, so PCR alone should not be used as a criterion for initiating or terminating the therapy. This should be supported by clinical, radiological, cytological and other microbiological findings to guide the clinician in decision making for appropriate therapy whenever possible.