Purpose: In some patients with velopharyngeal insufficiency (VPI), Hypernasality can persist after surgical management. Continuous Positive Airway Pressure (CPAP) is applied to these patients for treating hypernasality. The purpose of this study is to report follow-up results of postoperative CPAP therapy. Methods: After performing palatal lengthening, CPAP therapy was applied to three patients for eight weeks from July of 2008 to November of 2009. Perceptual evaluation, nasometry, and nasopharyngeal endoscopy were performed to evaluate hypernasality, nasalance and size of the gap at velopharyngeal port. Each evaluation was made before surgery, right after CPAP therapy and during follow-up of more than a year after CPAP therapy. Results: All of the patients showed improvement in hypernasality right after CPAP therapy according to the auditory perceptual evaluation, nasometry and nasopharyngeal endoscopy. But the improvement in hypernasality in these patients did not last during follow-up. Conclusion: In this study, our results suggest that CPAP therapy is effective in reducing hypernasality for postoperative VPI patients immediately after the therapy, but hypernasality may be worsen in some patients during follow-up. Therefore we recommend follow-ups after CPAP therapy to see if the efficacy of CPAP therapy lasts.