Nausea and vomiting of pregnancy affects nearly 75% of pregnant women. The exact cause is unknown. In most cases, it is a mild, self-limited condition that can be controlled with conservative measures and has no adverse fetal sequelae. About 1% of women develop hyperemesis gravidarum, which may result in adverse outcomes for the mother and fetus. Patients with nausea and vomiting of pregnancy should be evaluated for other causes, particularly if symptoms are unremitting or presentation is atypical. Initial treatment is conservative and includes dietary changes, emotional support, and vitamin B6 supplementation. Several safe and effective pharmacologic therapies are available for women who do not improve with initial treatment. Women with hyperemesis gravidarum may require more aggressive interventions, including hospitalization, rehydration therapy, and parenteral nutrition.