Pulmonary edema, a serious complication of pregnancy and the puerperium, can result in maternal and fetal morbidity and mortality. Pulmonary edema in pregnancy can be categorized by the primary mechanisms from which it results. An analysis of lung physiology using the Starling equation suggests that increased hydrostatic pressure, increased permeability, and osmotic imbalance can all lead to the development of pulmonary edema. These factors explain many of the common settings of pulmonary edema, including preeclampsia, tocolysis, and cardiac disease. This article will discuss the etiology and pathophysiology of pulmonary edema, how pregnancy influences it, and issues in its management.