BACKGROUND: Public antenatal care (ANC) clinics in Sweden contribute to low prenatal mortality and morbidity, through early detection of somatic risk factors, and referral to appropriate specialized care. Available statistics indicate, however, that this system is ineffective in dealing with psychosocial health problems, such as hazardous drug and alcohol use. Factors underlying this failure have not been explored. METHODS: An anonymous survey was carried out among all 207 ANC midwives in Stockholm County to establish their level of training within this problem area, clinical experience, theoretical clinical strategies, and actual clinical actions. FINDINGS: Responses indicate that ANC midwives: 1. are well aware of the health hazards of drug and alcohol use during pregnancy; 2. confirm having met and cared for subjects with hazardous substance use; 3. are familiar with specialized care resources available for this patient category; 4. make adequate choices regarding clinical action, i.e. problem identification and referral to specialized care, in hypothetical situations of encountering this patient category; 5. report consistent failure to actually exercise these choices in real clinical situations. CONCLUSIONS: A structured, clinically acceptable methodology needs to be developed in order for ANC clinics to fulfill their mission in the area of hazardous substance use in pregnant women.