A computerized consultation service developed by the Reproductive Toxicology Center, Washington, DC, provides summaries of the literature on more than 1300 chemical and physical agents. During the first five years of operation, the service was used to evaluate exposures in 1089 individuals. Only 3% of the exposures involved men. Of the 1053 exposed women, 85% were pregnant and 8% were planning pregnancy. In this latter group, potentially hazardous exposures were reported in 17%. Pregnant women were primarily exposed to medications, although exposures to chemicals at work and in the home constituted other important sources of inquiries. Excluding ethanol and tobacco, 19% of pregnant women were exposed to agents that are known or probable reproductive toxins. Ethanol exposure occurred in 27% of the sample and tobacco use was reported in 13%. These findings suggest that even women concerned about exposure to agents during pregnancy commonly use known or probable reproductive toxins. Physician access to reproductive toxicology information and patient education will be necessary to reduce these exposures.