Congenital bilateral macrostomia is a very rare deformity of the mouth, and it is still rarer to see cases of isolated bilateral macrostomia. Although the creation of a symmetric neocommissure is imperative, this presents a technical challenge. A review of the literature for surgical solutions revealed various techniques, but no cases in which a bilateral straight line repair was described and adopted. This report presents the case of a 3-month-old boy with isolated bilateral macrostomia for whom straight line closure was performed on both sides. At 1 year follow-up, the oral commissures are symmetric with aesthetically pleasing scars and no lateral migration.