Key content: The perinatal period confers an elevated risk of both relapses and new onset of mental illness. Suboptimal treatment can have a profound impact on maternal mortality and morbidity, neonatal outcomes and longer term child development. Most psychotropic medication can be used safely in pregnancy, with some notable exceptions. While decisions on the use of psychotropic medications in pregnancy are often complex and should be multidisciplinary, it is imperative that obstetricians and gynaecologists familiarise themselves with current literature to provide evidence‐based counselling and care. Existing guidelines on the use of psychotropic medication are largely aimed at psychiatrists, and to date there has been a lack of concise, digestible information with a focus on core knowledge for obstetricians and gynaecologists. We summarise existing evidence on the use of antidepressants, antipsychotics, mood stabilisers and sedatives in the perinatal period. For each drug class we describe the teratogenicity, impact on pregnancy, breastfeeding and the newborn. Learning objectives: To be familiar with common psychotropic medication used in pregnancy and the postpartum period. To understand key evidence on the safety profile of psychiatric medication in the perinatal period and apply this to individualised counselling.