Tuberculous lymphadenitis (TL) is a very common infection in human immunodeficiency virus (HIV)-infected patients. We performed fine-needle aspiration biopsy (FNAB) of enlarged lymph nodes in 57 HIV-infected patients to evaluate its usefulness in this population. We observed three cytologic patterns in 21 patients diagnosed as having TL: granulomatous lymphadenitis (GL) in 4 FNABs, necrotizing granulomatous lymphadenitis (NGL) in 7 FNABs, and necrotizing lymphadenitis (NL) in 12 FNABs. GL and NGL are already well-known and considered to be highly suggestive of TL. Our results support the idea that NL should have the same diagnostic value as GL or NGL. In the group of 12 patients with NL, TL was confirmed in 11 by microbiologic methods (7 by a positive Ziehl-Neelsen stain and 4 by a positive Löwenstein culture) and in the remaining patient by a biopsy that showed NGL with acid-fast bacilli. We conclude that FNAB is a useful, inexpensive, and safe technique for diagnosing TL in HIV-infected patients. The finding of a NL pattern is suggestive enough of TL to start antituberculous treatment.