Malignant epithelial tumours associated with autoimmune sialadenitis are rare in white races but occur more often in those of Eskimo or oriental descent. Ultrastructurally these tumours are squamous in origin, and they may arise from the epithelial component of autoimmune sialadenitis. The two cases reported are the first described in natives of this country, and in one, a case of parotid tumour, autoimmune sialadenitis preceded the development of undifferentiated carcinoma by 12 years; the other, a submandibular lesion, indicates some diagnostic difficulties that were found. This condition deserves wider recognition, as adequate primary treatment may result in long term survival.