We studied the rates of and factors associated with self-reported prior human immunodeficiency virus (HIV) testing in adult patients visiting an emergency department (ED) in the Bronx, New York City. A total of 1,744 consecutive noncritical adult medical emergency patients responded to a standardized interview administered by ED physicians. The interview included questions pertaining to demographic characteristics, prior HIV testing, and HIV risk behaviors. On multivariate analysis, female gender, younger age, history of weight loss, injecting drug use (IDU), syphilis, and genital herpes were all associated with increased reported prior testing rates. Race (i.e., black race) was an independent predictor of increased rates among male subjects; comparatively low rates were reported by patients with a first language other than English, patients lacking medical insurance, and highly sexually active, nonblack men. Increased HIV testing rates were reported by subjects with recognized HIV risk behaviors in a New York City ED population; however, substantial proportions of subjects at risk had not been tested. Programs of HIV testing and counseling need to include older, uninsured, and non-English-speaking segments of the population who engage in high-risk behaviors.