Alcohol and drug abusers present issues that complicate the informed consent process. The present study examined the practices of federally funded clinical investigators in obtaining informed consent from alcohol and drug abusers. Ninety-one (51%) researchers completed a 27-item survey on informed consent issues. The majority of investigators (57%) recruited participants susceptible to coercion; most used procedures to minimize coercion. Two thirds of researchers used objective means to determine competence to give consent and comprehension of consent forms. Virtually all investigators had policies to deal with suicidality, homicidality, or reports of child abuse; less than 1/2 informed participants of these limits to confidentiality. Almost 50% of investigators had dealt with intoxicated or suicidal participants; 12% had encountered homicidal participants; and 23% had encountered child abuse or neglect. Half of the sample used collateral data sources; about 1/2 of these obtained written informed consent from collaterals. Guidelines for informed consent with substance abusers are suggested.