IMPORTANCE: This study evaluates a technique to estimate cleft severity and tissue hypoplasia in patients with cleft palate. Current classifications are limited to the morphologic characterstics of the clefts. A new classification is proposed in relation to the palatal index, which allows more individualized surgical attention for the cleft palate. OBJECTIVE To evaluate the relationship of palatal index and cleft palate repair surgical outcomes (palatal fistula and velopharyngeal insufficiency) in patients with unilateral cleft lip and palate. DESIGN, SETTING, AND PARTICIPANTS Retrospective study performed by the Outreach Surgical Center Program Lima, Lima, Peru, of surgical outcomes of 152 consecutive pediatric patients, aged 12 to 15 months, with nonsyndromic unilateral complete cleft lip and palate treated during from 2001 to 2007. Findings were obtained at 1 to 5 years' follow-up. INTERVENTIONS Palatoplasty using the 2-flap technique plus intravelar veloplasty. Palate index was measured preoperatively with the patient under general anesthesia. MAIN OUTCOMES AND MEASURES Postoperative analysis via the χ2 test to assess the statistical significance of association between the palatal index and surgical outcomes. RESULTS Palatal fistula rates correlated directly with the cleft severity, as estimated by the palatal index (P = .01), but there was no association between postoperative velopharyngeal insufficiency and palatal index (P = .76). CONCLUSIONS AND RELEVANCE The palatal index was a good predictor of fistula development in the studied group. There was an association between the cleft severity and tissue deficiency (estimated using this index) and presence of palatal fistula. Further long-term study is needed to evaluate the relationship between the palatal index and maxillary growth.