Seven French-Canadian cases of clearcut oculopharyngeal muscular dystrophy (OPMD) had their muscle studied for the presence of intranuclear inclusions, and they were all positive. Inclusions of both “mature” and “immature” types were seen in our material. The presence of such intranuclear structures should be added to the criteria of the clinical picture and the family history for diagnosis of a case and inclusion of a family in further genetic studies. Reverse genetic studies of large families and biochemical studies of these intranuclear structures may help to understand the pathogenesis of this common disease in Quebec.