Psychiatric disease in the pregnant or breastfeeding woman presents a significant challenge. Untreated mental illness during pregnancy carries unfavorable impression for the mother, the child, the mother–child relationship and the family. Risks to the mother include self-harm/suicide, self neglect and reduced compliance with pre and post-natal care. Fetal underdevelopment, evidenced by low birth weight and small head circumference, is associated with antenatal maternal depression and anxiety. Short and long term consequences to the child may arise, including impaired bonding and attachment, cognitive disturbances, emotional problems and behavioral abnormalities. On the contrary treating the mother with psychotropic agents carries the risks of teratogenicity, toxicity and possible long-term neurobehavioral problems for fetus. Maternal medication during the first trimester of pregnancy, particularly between the third and eighth weeks of gestation, is most relevant with regard to morphological teratogenesis, whilst that during the second and third trimesters may have deleterious effects on growth and/or functional development and toxic effects. Clinical management is complex, involving competing risks to mother and offspring; the challenge lies in effectively treating mental illness, whilst minimizing exposure of the child to harmful medication. Several factors must be considered, including possible teratogenic effects of medication, the safety of medication during labor and delivery, possible long-term neurobehavioral effects and the effects of ongoing exposure during breast feeding. In the already pregnant women, the opportunity to reduce the dose of medication with a view to a (relatively) drug-free first trimester is often lost. Indeed by the time of presentation, pregnancy is often well progressed, with resultant exposure of the unborn child to potentially teratogenic medication. Maternal risks associated with drug withdrawal or reduction may predispose the unborn or breast-feeding child to more harm than the drugs themselves, mandating continued pharmacotherapy. No drug is absolutely safe; indeed the FDA has not approved any psychotropic medication for use during pregnancy or lactation. The clinician faced with the pregnant or breastfeeding woman therefore requires undertaking a risk-benefit assessment, tailored to the individual patient, with regard to the continuance or commencement of psychotropic medication. Relevant issues in such an analysis include the severity of the underlying psychiatric disorder, the consequences of leaving it untreated, and potential adverse effects of medication on both mother and child and the stage of pregnancy / breastfeeding. Treatment options and their risks and benefits should be discussed with the patient and care givers, and the possibility of delaying medication until the second trimester may be considered. Non-pharmacological interventions in the form of individual or group psychotherapy and enhanced psychosocial support should be considered before prescribing medications, particularly if the patient has mild symptoms or is in the early stages of pregnancy. If treatment is deemed appropriate, the smallest number of medications at the lowest possible dose consistent with control of the mental illness should be prescribed.