BACKGROUND Nonconvulsive status epilepticus (SE) is a frequent complication in critically ill patients in the intensive care unit. While seizures have been reported in association with subtentorial posterior fossa lesions, the frequency of occurrence of SE among these patients is not known. OBJECTIVE To examine prevalence, clinical features, potential risk factors, and outcome of SE among patients presenting with subtentorial posterior fossa lesions. METHODS Retrospective review of our hospital database was conducted to identify patients with posterior fossa lesions complicated by SE over 1 year between April 1, 2007, and May 1, 2008. METHODS Tertiary care setting. METHODS Patients with subtentorial posterior fossa lesions admitted to the hospital for neurological or neurosurgical care. METHODS Prevalence of SE, potential risk factors, and eventual neurological outcome. RESULTS Over 1 year, 13 of 501 patients (2.6%) admitted to the hospital with posterior fossa lesions had SE. Some patients had risk factors for SE such as sepsis, use of particular drugs, or intracranial bleeding, while others had no other clear identifiable cause. CONCLUSIONS Status epilepticus can be a potential complication in patients with posterior fossa cranial lesions and can be seen in up to 2.6% of such patients. Most have unfavorable outcome.