Nine infants with early-onset Haemophilus sepsis were seen between January 1973 and July 1977. Of the five isolated strains that were typed, only one was type B. All infants had respiratory distress, metabolic acidosis, and large alveolar-arterial oxygen tension difference gradients. Eight infants weighed less than 1,500 gm and died; one infant weighed 1,701 gm and survived. Roentgenograms in six of eight showed hyaline membrane disease. Pulmonary pathologic specimens in eight infants revealed hyaline membranes in six and polymorphonuclear leukocytes in the alveolar spaces in four. In two infants, small Gram-negative bacilli were noted within proteinaceous exudates in alveolar ducts. The route and time of infection in these infants with early-onset Haemophilus sepsis are unclear. However, the possibility that the infection occurs before birth and that these infants represent septically aborted prematures is suggested by the high incidence of prematurity in infants with early-onset Haemophilus sepsis and early detection of bacteremia in three infants.