This chapter describes the use of acoustic and aerodynamic procedures to evaluate speech and velopharyngeal (VP) function of individuals with cleft palate and/or VP dysfunction (VPD). The acoustics of vowel nasalization and the clinical use of the Nasometer are discussed followed by acoustic descriptions of obligatory nasal air emission and maladaptive articulations. An example of how to use acoustic measures to facilitate accurate differential diagnosis of perceptually similar speech symptoms is also included. Next, the pressure-flow method is presented both in its typical application and modified for use with young children. Aerodynamic characteristics associated with both normal function and VPD are illustrated. The value of pressure-flow testing as an objective assessment of VPD surgical outcomes is highlighted. The chapter ends with a description of a new aerodynamic metric of VPD that appears to have clinical utility.