CNS-active drugs are used relatively often during pregnancy. Use during early pregnancy may increase the risk of a congenital malformation; use during the later part of pregnancy may be associated with preterm birth, intrauterine growth disturbances and neonatal morbidity. There is also a possibility that drug exposure can affect brain development with long-term neuropsychological harm as a result. This paper summarizes the literature on such drugs used during pregnancy: opioids, anticonvulsants, drugs used for Parkinson's disease, neuroleptics, sedatives and hypnotics, antidepressants, psychostimulants, and some other CNS-active drugs. In addition to an overview of the literature, data from the Swedish Medical Birth Register (1996-2011) are presented. The exposure data are either based on midwife interviews towards the end of the first trimester or on linkage with a prescribed drug register. An association between malformations and maternal use of anticonvulsants and notably valproic acid is well known from the literature and also demonstrated in the present study. Some other associations between drug exposure and outcome were found.