Rosacea (acne rosacea, gutta rosacea, teleangiectasiasis faciei, cuperose) is a chronic recurring disease of polyetiologic nature that as a rule affects the face and proceeds in several stages. The authors report a case of Morbihan's disease (morbus Morbihan, persisting solid facial oedema, chronic persistent erythema and facial oedema), a rare form of rosaceae the diagnosis of which poses difficulty. Results of the treatment of the patient with isotretinoine confirms the possibility of successful management of this disease.