We aimed to describe nonconvulsive status epilepticus in terms of patient age, etiology, initial presentation, and electroencephalogram and neuroimaging findings. Twenty children with nonconvulsive status epilepticus were identified by a retrospective review of children who underwent long-term electroencephalogram monitoring in a pediatric intensive care unit. Age ranged from 2 months to 18 years, and in 30% of patients, the age was <1 year. Nonconvulsive status epilepticus occurred most commonly in children with prior epilepsy (35%) or congenital heart disease (25%). Prior to nonconvulsive status epilepticus, most had experienced isolated seizures (55%) or convulsive status epilepticus (20%), but some had only preceding mental-status change (25%). The most common etiologies were exacerbation of epilepsy (35%) and ischemic stroke (25%). No children aged <1 year had preexisting epilepsy. Electroencephalograms confirmed nonconvulsive status epilepticus immediately in 65%. Nonconvulsive status epilepticus lasted up to 8 days, and neuroimaging was abnormal in 82% of patients. Nonconvulsive status epilepticus occurs in a heterogeneous group of children, results from acute symptomatic etiologies in children aged <1 year, most frequently follows isolated convulsions but can occur with only preceding mental status change, and is often prolonged. These findings suggest that a high level of suspicion for nonconvulsive status epilepticus must be maintained, and long-term electroencephalogram monitoring may be indicated in a large number of patients.