Seizures are a recognized manifestation of neurosarcoidosis, but their clinical relevance is not well established. We reviewed the characteristics, clinical correlations, and prognosis of seizures in 79 patients with neurosarcoidosis. Thirteen (15%) of the 79 patients had seizures, and in eight patients (10%) a seizure was the first manifestation of neurosarcoidosis. These seizures were generalized tonic-clonic seizures in 12 patients (92%) and partial seizures in four patients (31%). The patients with neurosarcoidosis with seizures were more likely to have a progressive or relapsing clinical course and intracranial mass lesions (four patients [31%]), encephalopathy or vasculopathy (eight patients [62%]), or hydrocephalus (five patients [38%]). These central nervous system disorders, rather than the seizures per se, were responsible for most of the serious morbidity and the two deaths (15%) among our patients with seizures. Indeed seizure control was good in 11 (85%) of 13 patients treated with combinations of steroids and antiepileptic medications. Seizures are an important sign in neurosarcoidosis because they are associated with more severe and progressive or relapsing forms of central nervous system sarcoidosis and may be an early manifestation of such disorders.