Recruiting and retaining study participants in the drug treatment field and in many other areas of health research pose difficult issues. For example, in a recent review of treatment research to reduce mental disorders, the most frequently identified methodological problems concerned adhering to a strict randomized trial design and high attrition among study participants. These same problems commonly arise when subjects are drug-abusing women with children, but the problems are more complex because they occur in combination with other unique issues related specifically to this population. To advance knowledge about the treatment of addiction among pregnant women and women of childbearing age, investigators must adhere to a strict experimental research design while concurrently providing clinical services. The Perinatal-20 Treatment Research Demonstration Program has provided a beginning knowledge base that can be used to refine and expand future drug treatment efforts. Additional research is needed to study a representative spectrum of the female population and to address tensions between research and clinical requirements. Special issues affecting research on pregnant and parenting drug-abusing women are examined that encompass addiction severity, involvement with the legal system, housing, interpersonal relationships, parenting responsibilities, employment, and the need for comprehensive services. 15 references