One of the forms of congenital myoclonia in pigs is described for the first time. Epizootologic, clinical, and morphological studies on the syndrome have been carried out, and a description of the clinical, morphologic, and histopathological findings are given. All pigs that exhibited the syndrome have shown double and triple hypoplasia of the cerebellum. Results obtained so far give no reason to assume, resp., demonstrate the etiologic essence of the syndrome. Investigations in this connection are under way.