This study aimed to analyze changes in resonance and speech articulation after midface advancement in syndromic craniofacial patients and to assess the influence of craniofacial diagnosis and the presence or absence of a cleft palate. This study is a retrospective analysis of resonance and speech articulation in patients after midface advancement. This project was carried out in a multidisciplinary pediatric craniofacial service. Eighteen patients underwent midface advancement between 2002 and 2009. Three were excluded because of inadequate records or presence of tracheostomy. Midface advancement was done by Le Fort III, facial bipartition, or monobloc, either conventional surgery or distraction osteogenesis. Outcomes include perceptual assessment of articulation and resonance using GOS.SP.ASS.98 revised and recommendation for speech surgery. Hypernasality scores decreased in 7 patients (46.7%), and 5 patients were recommended for speech surgery. Hyponasality scores improved in 10 patients (66.7%), were unchanged in 3 patients (20%), and decreased in 2 patients (13%). Articulation changed (improved) in 1 patient (6.7%) only. Hypernasality scores decreased in 33.3% of Crouzon and 71.4% of Apert patients. Five patients had a cleft palate, 4 had Apert syndrome, and hypernasality scores decreased in 3 patients. Of 3 patients with Apert syndrome but no cleft palate, 2 (66.7%) also had a decrease in hypernasality scores. Our findings suggest a high incidence of deterioration in velopharyngeal function after midface advancement, particularly in Apert syndrome, regardless of the presence of a cleft, and an improvement in hyponasality, but minimal change in articulation. Larger prospective multicenter studies are required to investigate these findings further.