The phenomenon of mass, frenzied dancing affected large populations in various parts of Europe from the thirteenth century and lasted, on and off, for three centuries. The exact aetiology of the Dancing Plague (or Dancing Mania) is still unclear. Retrospective historical review of this public health problem reveals claims for causative factors including demonic possession, epilepsy, the bite of a tarantula, ergot poisoning and social adversity. It seems unlikely that Dancing Mania resulted from a single cause but rather resulted from multiple factors combining with a predisposing cultural background and triggered by adverse social circumstances. Dancing Mania remains one of the unresolved mysteries of public health.