The aim of this study was to analyze the location and cause of postoperative bleeding after posterior pharyngeal flap pharyngoplasty and to investigate the surgical techniques with the goal of treating the bleeding. The patients received posterior pharyngeal flap pharyngoplasty in the Cleft Lip and Palate Treatment and Research Center of Shanghai Jiaotong University School of Medicine from January 2003 to December 2014, and postoperative bleeding in the surgical area was retrospectively analyzed. According to the record of the exploration of hemostasis, the locations and causes of the bleeding were summarized. In the 12-year study, a total of 1037 patients received posterior pharyngeal flap pharyngoplasty, including 621 males and 416 females with ages ranging from 4 to 40 years and a mean age of 13.7 years. Among these patients, 7 individuals (0.68%) experienced significant postoperative bleeding with the exploration of hemostasis. All patients were male, aged 5 to 26 years with a mean age of 15.7 years, and all were sent back to the operating room for exploration of hemostasis under general anesthesia. The sites of bleeding included 2 patients (28.6%) of the soft palate, 2 patients (28.6%) of the pharyngeal flap pedicle, and 3 patients (42.8%) of the nasopharynx. In posterior pharyngeal flap pharyngoplasty, particular attention should be paid to the protection of the blood vessels in the soft palate and the treatment of the vascular pedicle. Postoperative bleeding is very dangerous and generally requires immediate exploration in the operating room under general anesthesia.