The authors report on three cases of staphylococcal cerebrospinal fluid (CSF) infection with normal white blood cell count and normal CSF glucose level in repeated lumbar CSF examination. All three children (2 months, 17 months and 4 years old) have been operated for neonatal hydrocephalus with setting of a ventriculo-peritoneal shunt one to two months before. Infection was suspected because of fever without evocative clinical signs. In two cases plasma C reactive protein level was increased, and in all three cases a leucocytosis was present. The diagnosis was made by bacteriological examination of the ventricular CSF. Both surgical and medical management were required and the bacteriological outcome was favourable. Since neurological sequellae may occur if the treatment is delayed such atypical infection needs to be promptly assessed.