Background:The authors aimed to report a hitherto undescribed class of patients with the obvious phenotype of a novel soft palate dysplasia (SPD) combining unilateral soft palate hypoplasia with a fully developed uvula. The authors also aimed to investigate and evaluate the corresponding surgical approaches. Methods: Twelve patients were clinically diagnosed with SPD. Clinical examination, including radiographic tests, was performed to characterize the congenital deformity. The effectiveness of velopharyngeal closure and speech were tested preoperatively and postoperatively. Results: SPD was featured with velopharyngeal insufficiency, food regurgitation, and speech disorders. It was commonly manifested as structural deformities of the soft palate, tongue palatine arch, pharyngeal palatine arch, and pterygomandibular fold, but with complete uvula shape. According to radiographic analysis, in five patients, the lateral pterygoid processes were poorly developed, and other malformations were present. Velopharyngoplasty based on the unilateral posterior pharyngeal flap can well restore the velopharyngeal closure and speech intelligibility without respiration obstruction. Conclusions: SPD is characterized as congenital velopharyngeal insufficiency manifested as a primary soft palate defect. It is highly associated with other physical deformities but independent of conventionally known syndromes. The cause may be an abnormal development of the pterygoid process. Unilateral velopharyngoplasty based on the posterior pharyngeal flap is a great technique to repair SPD.