Commonly referred to as "poppers," inhaled nitrites have a long history of abuse. Poppers are rapid-onset, short-acting potent vasodilators that produce a rush characterized by warm sensations and feelings of dizziness. Poppers sometimes are used to facilitate anal intercourse because of their actions on the anal sphincter. Epidemiologically, the frequent use of nitrites by men who have sex with men has led some experts to implicate these chemicals in the pathogenesis of Kaposi's sarcoma and acquired immunodeficiency syndrome. Controlled clinical trials to examine this potential correlation have not been conducted, and the use of nitrites simply may be a marker for other high-risk behaviors such as unprotected sex. Although regulated in the United States, many nitrite compounds and isomers are sold at various venues including bars, bookstores, and over the Internet. Adverse effects associated with these products vary from mild allergic reactions to life-threatening methemoglobinemia. The potential for drug-drug interactions and a propensity toward unsafe sex also exist. Clinicians should be familiar with the populations most likely to abuse these agents and with the clinical effects and management guidelines for acute ingestions.