The lifetime incidence of mood disorders is twice as great in women compared with men, with the highest risk occurring during the childbearing years. The management of mental illness during pregnancy and lactation is a particularly complex clinical situation. The cornerstone of such a clinical decision is a completion of an assessment of the risks of the illness vs the risks of treatment. The following article reviews the factors influencing infant outcome and outlines the essential elements of the process of determining risk for the use of psychotropics in women during pregnancy and lactation. As the available data rapidly change, the facets of the risk benefit assessment are consistent and often the issue of specific medication is decided by prior history and exposure.