A case of MV with pronounced nasal symptcms in a 12-year-old girl is described. It is important that the patient should come under treatment as early as possible because of the long-term prognosis, and here the otologist can make his contribution. Since the completion of this paper, another patient with suspected mucoviscidosis has been examined at the clinic. This is an 8-year-old girl who was referred to the clinic because of recurring nasal polyps and otitis. A polyp was found in the left nostril and there was opacity of the maxillary sinuses. The amount of sodium in sweat, determined by pilocarpine iontophoresis a.m. Gibbson & Cooke, was increased (81 and 86 mEq/l) and there was an elevated sodium/chloride ratio (5.4 and 6.1). The patient has been admitted to the Paediatric Department of Blegdams Hospital for further examination for mucoviscidosis.