During February to June 1987, one hundred and sixty one babies admitted to Harare Neonatal Unit had positive blood cultures, giving a sepsis rate of 21/100 live births at Harare Hospital. The case records of these 161 babies were reviewed and compared with records of 50 babies admitted from the same catchment area and during the same time period but who had negative blood cultures. Babies with early (less than 48 hr) onset or late onset sepsis tended to have lower birth weights and shorter gestational ages than controls. Significant risk factors in maternal history were poor antenatal care and prolonged rupture of membranes. Hypothermia, respiratory distress, jaundice and hypoglycaemia were all common findings in babies with sepsis. Staph. aureus and Group B streptococci (GBS) were the most common isolates in both early and late onset sepsis, with Esch. coli and Klebsiella sp. being more common in early than in late onset disease. Cultures from the genital tract were obtained from 28 of the mothers whose babies developed sepsis. Only rarely, however, was an organism with similar identity and antibiogram to that isolated from the blood culture of the baby obtained from the mother. Nevertheless mothers of blood culture positive babies showed high carriage rates of GBS, B. melaninogenicus and Klebsiella. The overall mortality in sepsis cases was 28.5 pc, but mortality was discouragingly high where coliforms or Staph.epidermidis were isolated.