Homeless women in the United States comprise a subpopulation at high risk for substance abuse, with rates of substance use disorder ranging from 16% to 67%. Despite the need for treatment that such high rates imply, relatively few substance-abusing homeless women avail themselves of formal treatment. The fact that they tend not to utilize formal treatment services is especially problematic among homeless women of reproductive age, who are not only themselves at risk of health-related problems but who place their fetuses and children in danger of multiple negative consequences. The imbalance between treatment need and treatment access suggests that homeless, substance-abusing women are facing severe barriers to care. Although identifying barriers to their treatment access is crucial if this imbalance is to be remedied, very little empirical research has been done in this area. This article presents an overview of current knowledge about barriers to substance abuse treatment for women generally and for homeless women specifically, and proposes a comprehensive empirical strategy for redressing the lack of information on homeless women's access to substance abuse treatment.