The results of correction of nasal defects in patients with unilateral cleft lip are often disappointing because the malformation has not been clearly understood. Many illustrations of deformity of the lower lateral cartilage are anatomically incorrect. To understand the true nature of the deformity, the surgeon must have a fundamental knowledge of the musculature of the region, particularly the nasolabial portion of the orbicular muscle and the nasal muscle complex. Correction of the nose must establish a physiological nasal airway, which is necessary for good subsequent facial growth. This can be accomplished without either excessive scarring or a cartilage graft, by careful reconstruction of nasolabial muscular integrity with the anterior nasal spine and the septopremaxillary ligament, functional repair of the orbicular muscle, and finally by raising and rotating the displaced alar cartilage. These principles apply equally to both primary and secondary operations.