Background: Conventional treatment for cleft lip and palate patients is lip repair at three to four months and then palatal repair at nine to 12 months of age. However, for the patients who delay seeing a doctor especially in a developing area such as Northern Thailand, simultaneous lip and palate repair is performed at 12 to 18 months of age or later, depending on the age at the first visit. It is a common belief that patients with cleft lip and palate will be behind non-cleft patients in early development phonemes because of the open palate. This delay persists until the palate is repaired and on into the postoperative period. This proposition has not been proven with long-term clinical outcomes in one-stage repairs. Objective: To investigate the effects of one-stage repair on speech assessment, hearing, and incidence of palatal fistula. The results were compared with conventional two-stage surgical repairs. Materials and Methods: The present study was designed two groups. Group 1 consisted of 25 children (mean age 11.28±1.93 years) treated with a one-stage repair. Cleft lip, palate, and alveolus were repaired at a single surgical session in the first 18 months of life (mean age at the time of surgery 13.52±4.51 months). Group 2 consisted of 17 children (mean age 11.02±2.23 years) treated in two-stage surgical repairs. Lip repair was performed at a median age of 4.01 months (IQR 3.62 to 5.46), and palate repair was performed at a mean age of 13.54±4.14 months. Both groups underwent cleft lip and palate repairs at the Division of Plastic Surgery, Department of Surgery, Faculty of Medicine, Chiang Mai University between January 1, 2004 and December 31, 2010. Speech and hearing for all patients were evaluated by experienced ENT doctors. The palatal fistula was evaluated by the same plastic surgeons. Results: One-stage repair showed significant normal articulation and less articulation disorder when compared with two-stage surgical repairs. However, no significant difference was determined for other speech assessments, hearing, and incidence of palatal fistula. Conclusion: Because one-stage repair seems to have a more positive influence on articulation, and both surgical treatment protocols give similar results on speech assessments, hearing, and incidence of palatal fistula, regardless of the timing of the surgery, the one-stage repair is not inferior to conventional two-stage surgical repairs for patients in developing areas. This is due to several important advantages, such as less hospitalization, lower cost, and less chance of nosocomial infection. Keywords: One-stage repair, Speech, Hearing, Palatal fistula, Cleft lip, Palate