Purpose: The authors would like to introduce two patients who presented with velopharyngeal inadequacy. We emphasize the importance of nasaopharyngeal endoscopy in evaluating the velopharyngeal function and the usefulness of biofeedback trial therapy. Methods: Two patients visited our clinic due to velopharyngeal inadequacy. Both of the patients showed hypernasality, nasal emission and compensatory articulation such as glottal stop. During oral examination and nasopharyngeal endoscopy both showed no evidence of structural deformities. One inconsistently showed a small gap during articulation. The other showed a rather large gap during compensatory articulation. Both received a simultaneous biofeedback trial therapy using the nasopharyngeal endoscope. Results: Both patients were successfully diagnosed and treated at once using biofeedback trial therapy with nasopharyngeal endoscopy. By giving direct visual feedback to the patient, they were both able to achieve complete velopharyngeal closure during production of 2~3 nonsence syllables and hypernasality was not detected in both of them. Conclusion: The authors were able to help patients with velopharyngeal inadequacy to have velopharyngeal closure through biofeedback trial therapy. The accurate evaluation of velopharyngeal function and the possibility of closure prevented unnecessary operations.