Bacterial studies on breast milk collected by an electric suction pump from 44 postpartum mothers were conducted. All samples had bacterial growth, while 84% had organisms identical to those cultured from the mother's nipple. Colony counts varied greatly, with a median of 8700 and mean of nearly 20,000. In 30% of the milk samples, potentially pathogenic organisms were recovered. The significance of these results and collection techniques that might modify these results are discussed.