The fact that a small cancer hidden in the chest, abdomen, or pelvis could destroy or damage portions of the nervous system, such as cerebellar Purkinje cells or cholinergic synapses, has intrigued neurologists since paraneoplastic syndromes were first described. In 1965, when little was known about their pathogenesis, a full issue of the journal Brain and an international symposium were devoted to paraneoplastic disorders. In this decade, the discovery of several paraneoplastic antibodies that react with both the nervous system and the causal cancer has rekindled interest in these syndromes (Table). Several other factors make these rare syndromes of clinical and scientific interest. A recent review by Dalmau and Posner contains a more comprehensive bibliography of paraneoplastic syndromes.