Since 1980 the Hazard Evaluation System and Information Service has responded to over 11,000 inquiries regarding workplace health hazards. Of 2,424 inquiries in 1986, 593 (24%) concerned hazards to pregnancy. This represents a 17-fold increase since 1981. Most pregnancy-related inquiries were from employees (70%) and health care providers (23%). Referral sources for the employees calls were almost exclusively individual health care providers or institutions that provide health care or health counseling, or both. These data suggest that pregnant employees seek information on their own or from health care providers instead of from employers. Of the inquiries, 80% were for general pregnancy hazard information; 20% involved symptomatic pregnant employees. Most inquiries concerned employment in the services (58%) and manufacturing (26%) sectors. Organic solvents, pesticides, acrylic nail-grooming products, lead, and video display terminals were among the agents about which callers inquired most frequently.