Four infants acquired meningitis within ten days in the same maternity unit. They were not severely ill. Fever was neither high nor long-lasting, and sedimentation rate, leukocyte count and C-reactive protein did not suggest bacterial infection, In contrast, there was a marked pleocytosis in the cerebrospinal fluid in three children with leukocyte counts between 2660 and 5000 cells, predominantly granulocytes. As pathogens enteroviruses were identified. One father and one brother of the infants had mild fever and had identical enteroviruses in their stools, and one other father and two further neonates were unaffected carriers.