Congenital bilateral macrostomia, a transverse facial cleft, is a rare deformity of the mouth; when it occurs, it is usually unilateral. Many procedures have been developed for correction of macrostomia and most of them use the noncleft side to mark the reconstructed commissural position. In cases of bilateral forms, the surgeon must define the commissural position without a normal side as a reference. Most of the reported procedures place the scars at the mouth angle or at the lower lip, which result in an unnatural appearance. We report a successful correction for a 4-month-old baby girl with bilateral macrostomia using vermilion square flap technique. The scar is placed at the upper lip. At one month follow-up, the oral commissures are symmetric, the scars are inconspicuous, and the overall balance of facial contour and lip is excellent.