To assess the bacteriological quality of unpooled expressed breast milk, a pilot bottle sample of each donation was examined before the milk was given to the neonate. Provided the milk did not contain greater than 2500 organisms/ml or potential pathogens it was used unheated. Milk containing between 2500 and 5000 organisms/ml and no potential pathogens was used after pasteurisation. Using these criteria, 67% of 460 donations were acceptable. However, because the bacteriological quality varied, 45% of domiciliary donations were discarded compared with only 29% of those from hospital.