We report a case of intrauterine Klebsiella pneumoniae infection that resulted in premature rupture of membranes and fetal demise at 20 weeks' gestation in a pregnancy achieved by in vitro fertilization. Postmortem findings included massive panlobar pneumonia, the presence of abundant gram-negative, rod-shaped bacteria within the pulmonary air spaces and the lumen of the gastrointestinal tract, and fetal lung and blood cultures positive for Klebsiella pneumoniae. The placenta showed severe acute chorioamnionitis associated with a brisk fetal inflammatory response (umbilical cord and chorionic plate vasculitis). Marked pancreatic fibrosis was noted, indicative of a preceding necrotizing pancreatitis. In spite of this fulminant histopathologic evidence of intrauterine infection, the infection was clinically silent. This represents, to our knowledge, the 1st reported case of fatal intrauterine Klebsiella pneumoniae infection fully supported by conclusive fetal and placental histopathological evidence.