A new technique for digestion of sputum incorporates the mucolytic agent N-acetyl-L-cysteine as digestant, and employs concentrations of sodium hydroxide that vary from one-fourth to one-half of the amount normally used for sputum digestion. In these studies, results have shown marked increases both in number of specimens positive for acid-fast bacilli and total colony counts per specimen. The newly described method also is faster and easier to apply than any of the methods currently in vogue.