Recovery of Mycobacterium tuberculosis from sputa treated with cetyl-pyridinium chloride (CPC) and stored for 20 +/- 9 days was significantly higher than that from sputa that were untreated and processed by the N-acetyl-L-cisteine-NaOH method. Addition of CPC is useful for isolation of M. tuberculosis from sputa subjected to long-term storage received from remote areas of the world.