Three children from a family of eight, had a cystic fibrosis diagnosed by Sweat test. Two of these had a nasal polyposis wigh widening of the nose, ethmoid and intercanthal distance. Every cases of this rare type of nasal polyposis in children observed since 1953 (Sweat test) and related in the litterature, had cystic fibrosis. It is concluded that cystic fibrosis may be the one only, cause of nasal polyposis with widening of the nose.