Displacement of the lateral crus of the alar cartilage of the nose in cleft lip is demonstrable in diagrams showing the pathological anatomy of this deformity. An account is given of our method used for several years, whereby the lateral limb is returned to a more natural position, alar convexity is restored, and the angle between the limbs is corrected. Two flaps taken from the inside surface of the nostril are alternated. The caudal one is a full-thickness flap composed of vestibular skin, while the cranial flap comprises the cartilage and the vestibular mucosa; the lateral limb is left attached to the mucosa. Alternation does not require any interruption of cartilage continuity, so there is no risk of surgical damage to the perichondrium and cartilage in young subjects. The two limbs (particularly the lateral one) are positioned in such a way that their normal growth can be expected, as shown by the aesthetic results on follow-up after a period of many years. This method is a primary reconstruction technique of the ala nasi, applied at the same time as the lip repair and compatible with current methods.