Submucous cleft palate (SMCP) is a subgroup of cleft palate that can present as velopharyngeal insufficiency due to muscle displacement. The pharyngeal flap and Furlow palatoplasty have been introduced to correct SMCP patient with velopharyngeal insufficiency. However, pharyngeal flap and Furlow palatoplasty can occur various complications. We consider the overlapping intravelar veloplasty (IVVP) can overcome these complications. Therefore, we present the speech outcomes of overlapping IVVP for the treatment of patients with SMCP. We retrospectively reviewed 12 patients with SMCP underwent overlapping IVVP between April 2016 and October 2018. The patients who underwent speech evaluation, nasometry, and nasoendoscopy before and after surgery and who were followed up for >18 months were enrolled in this study. The average age of the patients was 5 years (range, 3-11 years) and the postoperative follow-up period ranged from 18 to 24 months (mean, 20 months). The preoperative perceptual speech evaluation was moderate and the postoperative evaluation was normal ( P < 0.01). The preoperative and postoperative nasalance scores obtained using a nasometer were 37.00 and 12.50, respectively, ( P < 0.01). Preoperative and postoperative velopharyngeal movements were grades 3 and 0, respectively, ( P < 0.01). Our study showed that overlapping IVVP could provide successful correction of velopharyngeal insufficiency in patients with SMCP, including relatively old patients.