Nasopharyngoscopy is a minimally invasive endoscopic procedure that allows visual observation and analysis of the velopharyngeal mechanism during speech. It can be used to assess both anatomic and physiologic abnormalities of the velopharyngeal valve. In cases of suspected velopharyngeal insufficiency (VPI), nasopharyngoscopy is particularly useful in determining the size, location, and cause of the velopharyngeal opening. This information is very important for surgical planning. Nasopharyngoscopy is also  useful in the assessment of secondary surgery that was done for VPI. It can help determine the need for revision and the type of revision surgery that is most likely to be successful. The purpose of the chapter is to explain how nasopharyngoscopy is used in the evaluation of velopharyngeal function. This chapter includes specific tips for achieving a successful examination in children as young as age 3. Finally, important observations from nasopharyngoscopy are described.