We report a term neonate who developed early-onset sepsis due to Morganella morganii. The child was vaginally delivered after a short labor, and presented signs of perinatal asphyxia. Blood cultures taken soon after birth and from mother's lochia were positive for this microorganism. The infection was unresponsive to treatment with cefotaxime, to which the microorganism was susceptible, and the infant died at 17 days of age. M morganii is an opportunistic and uncommon pathogen, causing disease mainly in patients with underlying illness or after surgery. It is a rare perinatal pathogen, causing severe disease in premature infants, in association with maternal chorioamnionitis and premature rupture of the membranes (RevMéd Chile 2009; 137: 1201-4).