Mandibular distraction osteogenesis (MDO) is an effective treatment modality for children suffering from upper airway obstruction from Robin Sequence (RS). Mandibular distraction osteogenesis has been shown to have positive effects on oral feeding and for relieving respiratory obstruction, but its effects on postoperative weight gain are poorly understood. This study quantitatively analyzes weight gain following MDO. A retrospective chart review identified 22 RS children who underwent MDO. Patient weight data, feeding methods pre- and postoperatively, and polysomnography data pre- and postoperatively were collected. Each patient's weight plotted over time was then compared with his or her closest standardized growth curve, and linear regression analysis was utilized to quantify patient growth by calculating actual and expected average daily weight gain (g/d). Percentile changes were analyzed as well. Children gained significantly less weight than expected from birth to time of MDO and significantly more weight than expected from MDO to device removal, MDO to 6 months postoperatively, and MDO to 12 months postoperatively. The average growth percentile for the cohort was 37.3 at birth, declined to 22.7 by MDO, and increased to 28.5 and 33.5 at device removal and 6 months postoperatively, respectively. More than 70% of children were exclusively orally fed within 6 months of MDO. Children with isolated Robin Sequence had superior weight gain than children with syndromic Robin Sequence following surgery. In conclusion, MDO helps improve weight gain following surgery, particularly for infants with isolated Robin Sequence, and has positive effects on oral feeding and respiration.