Neonatal sepsis caused by Haemophilus influenzae is characterized by an early onset syndrome associated with pneumonia, shock and neutropenia. Over a 30-month period 13 infants referred to this hospital had early onset H. influenzae sepsis. Obstetric complications included preterm labor (92%), prolonged rupture of membranes > 12 hours (63%), maternal fever (64%), chorioamnionitis (43%), vaginal discharge (44%) and premature rupture of membranes (15%). All 13 infants were symptomatic at delivery and 7 required immediate intubation. Pneumonia and respiratory distress were the prominent clinical findings. H. influenzae was isolated from infant blood, maternal blood, placenta and genital tract. Isolates were predominantly non-type b, beta-lactamase-negative. A study to determine the prevalence of H. influenzae colonization of the genital tract among women attending clinic at the hospital with the most cases showed a rate of 0.3%. Perinatal risk factors and clinical findings in the infants are similar to disease caused by other organisms associated with early onset sepsis.