Separation of the nasal and oral cavities by dynamic closure of the velo-pharyngeal port is necessary for normal speech and swallowing. Velo-pharyngeal dysfunction (VPD) may either follow repair of a cleft palate or be independent of clefting. While the diagnosis of VPD is made by audiologic perceptual evaluation of speech, identification of the mechanism of the dysfunction requires instrumental visualization of the velo-pharyngeal port during specific speech tasks. Matching the specific intervention for management of VPD with the type of dysfunction, i.e. differential management for differential diagnosis, maximizes the result while minimizing the morbidity of the intervention.