During routine bacteriological culturing of nursery fomites in a hospital, Pseudomonas aeruginosa was found in sinks and in faucet aerators. Water from these faucets was used to wash hands and to clean equipment, and may have contributed to the difficulty encountered in cleaning incubators free of Pseudomonas. The only other fomites providing a moist environment and culturing Pseudomonas were sink sponges. Handwashing within the room with the contaminated water could easily have transmitted Pseudomonas to susceptible infants. In the nursery for premature infants, one of the 7 infants had a persistent nasopharyngeal culture of Pseudomonas, which was also obtained in pure culture from his lungs after death; the other 6 were not infected. Cultures of the humidifying water, the infant's Isolette, air of his Isolette, and of the room were negative for Pseudomonas.