The presenting features, clinical course and outcome of 19 patients with a diagnosis of CNS sarcoidosis are described. In two-thirds of the patients the initial features of sarcoidosis were neurological; half of them had an acute monophasic illness and half a chronic progressive or relapsing course. A favourable outcome was recorded unexpectedly during a study period of one to 16 years for two-thirds of the patients. The course of the disease in four patients suggested multiple sclerosis thus emphasising the importance of considering the possibility of CNS sarcoidosis in patients with suspected demyelinating disease.