Recent trends in the progression of the AIDS epidemic in the United States indicate that women's rates of acquiring HIV are escalating more rapidly than are men's. Consequently, there has been both an increasing interest in and a need for research targeting substance-abusing women's involvement in HIV risk behaviors. In recent years, strong suggestive evidence has arisen to suggest that women who use crack cocaine are at an elevated risk for acquiring HIV, probably as a result of their involvement in high-risk sexual behaviors. The present study is based on a sample of 1723 women from 22 locales around the United States who used crack cocaine at least once during the previous 30 days but who reported never having injected drugs at any point in their lifetime. Women were divided into four groups based on their frequency and intensity of using crack. In subsequent analyses, this grouping was used to predict the extent to which female crack users engage in five sexual risk behavior measures (number of sexual partners, number of drug-injecting sexual partners, number of times having sexual relations while high on alcohol and/or other drugs, number of times trading sex for drugs and/or money, and proportion of all sexual acts involving the use of protection). The data revealed that the women who used crack with the greatest frequency and the greatest intensity were the most heavily involved in risky sexual behaviors. They differed quite sharply from their lower-intensity and/or lower-frequency crack-using counterparts in terms of their HIV risk behavior involvement and in terms of their actual HIV seroprevalence rates.