This study evaluates the substance abuse history and treatment needs among a cohort of 308 women enrolled at the HHSCC, a comprehensive HIV-care program, in St. Louis, Missouri, from 1995 to 1998. The study revealed several findings: a greater prevalence of substance abuse history was identified among these Midwestern women than initially anticipated; over half had abused alcohol and marijuana, and nearly one-third had used cocaine; tobacco smoking co-occurred with abuse of alcohol and other drugs; substance abuse behaviors were more likely to be found in the older women; and the history of intravenous drug use was low among the women enrolled at HHSCC. A concerned finding was that only 43.9 percent of those women identified as needing substance abuse treatment had received such treatment. Several reasons for this were identified and included: women may be unwilling to accept that they have a substance abuse problem, are not ready to undergo treatment or therapy, and have a scarcity of substance abuse treatment programs and support available. The study noted that having a history of abuse of various substances was, in fact, associated with a greater number of nurse/social work-case management interventions, even if not directly related to substance abuse treatment. With regard to medical care visits, adherence with quarterly medical follow-up was associated with prescription of HAART (highly active antiretroviral therapy) in both 1997 and 1998, but not associated with the need for substance abuse treatment. However, women needing substance abuse treatment were less likely to have been prescribed HAART in 1998. Study implications are: (1) communities serving women with HIV need to be sensitive to the risks and impact of substance abuse, before and after HIV transmission; (2) there is ongoing debate as to the feasibility of engaging substance abusers in HAART; (3) the regional diversity of patients reveals an additional challenge for staff to provide services that are tailored for women living in diverse urban, suburban, and rural areas; (4) comprehensive HIV care programs may want to consider assessment of substance abuse and treatment referrals as continuous quality improvement indicators in patient and program level evaluations; and (5) the data has led to the redesign of methods used in initial and annual assessments of substance abuse.