This report describes an outbreak of nosocomial infections due to echovirus type 11 among premature and/or handicapped infants in an intensive care unit. Four patients became ill within a short period of time and echovirus 11 was recovered from several of their specimens. The illnesses were clinically suggestive of bacterial sepsis and/or bacterial meningitis. Each of the four infants who became ill was in an isolette for a period of from 20 to 54 days before onset of illness. Three of the four patients became ill within 24 hours of one another which suggested a common exposure at nearly the same time. No index case could be identified, but it appears that this outbreak of enteroviral infections was due to inadequate hand washing by personnel. The outbreak was halted by removing the infants to an infectious disease unit and by closing the involved unit to new admissions for seven days.