This was a retrospective case-control study over 14 years comparing characteristics of neonates who developed E.coli bacteraemia with matched infant controls whose mothers were colonised with E.coli on high vaginal swab but who did not develop bacteraemia. Data was obtained from maternal and neonatal charts, the laboratory data-base was analysed to identify possible risk factors for E.coli bacteraemia. 21 cases and 38 controls were identified. The data showed no difference in gender, maternal age, white cell count, or cord pH. Significant differences were found in gestation (33 vs. 39.5wks p<0.01), weight (1.64 vs. 3.08 kg p<0.001) and duration of preterm, pre-labour rupture of membranes (pPROM) (6 vs. 2.9 days p=0.04) between cases and controls. Risk factors for E.coli bacte-raemia were identified, most notably duration of pPROM. A re-evaluation of antimicrobial therapy in neonates with a maternal pPROM >5 days is advised.