Splenic avulsion in pregnancy is a rare condition that carries a high risk of death to both mother and fetus. The authors describe a 30-year-old woman with hyperemesis who had spontaneous avulsion of the spleen at 30 weeks' gestation. She underwent a splenectomy and cesarean section, resulting in a stillborn fetus. The authors theorize that violent vomiting resulted in splenic avulsion. Prompt surgical intervention by a general surgeon and obstetrician is required in such cases.