During a 4 year period, 79 infants aged from 1 month to 2 years suffered a status epilepticus (SE). The seizures were most often either generalized of tonic-clonic or clonic type, or unilateral clonic; they lasted or were repeated with persistent unconsciousness between the seizures for periods ranging from 30 min to several days. All the cases of SE lasting over 6 h resulted from a recognizable acute brain injury, whereas 11 of 14 cases lasting 1 h or less were cryptogenic. In 2 cases only, the neurological status was worse after the status, apparently as a result of the seizures themselves. The authors discuss the hypothesis of purely febrile HH syndrome and point out the importance of detailed clinical ictal and interictal characteristics for the etiological approach.