In most cases, after successful correction of primary cleft lip deformity, some problems remain to be solved. One of them is nostril sill depression, which should not be overlooked in cleft lip repair. However, there have been few reports on the anatomy of the depressed nostril sill and methods for augmenting the sill depression. The anatomy of the depressed nostril sill, its relationship to surrounding tissue, and the gross features of nostril sill depression in cleft lip deformity were reviewed, and a method in which a scar flap and a suture-fixation technique are used was developed for augmenting the depression. The clinical results of this method in 16 patients are presented.