BACKGROUND: The purpose of this prospective study was to develop and validate an objective means of grading the presurgical unilateral cleft lip nasal deformity. Our hypotheses are that expert cleft surgeons can reliably rank patients according to their subjective assessment of the degree of unilateral cleft lip nasal deformity and that objective anthropometric measurements correlate consistently with this subjective assessment. METHODS: Forty consecutive infants with unilateral cleft lip nasal deformity were subjectively ranked according to the degree of deformity on standardized presurgical photographs by four senior cleft surgeons. Internal agreement was assessed. Correlations between presurgical anthropometric parameters and the subjective panel rankings were determined. To test the reproducibility of subjective ranking, a random subset of images (n = 15) was also ranked by four external expert cleft surgeons of international reputation. RESULTS: There was extremely high agreement of subjective ranking by the expert panels (interclass correlation coefficient, 0.95 for the internal panel and 0.94 for the external panel) and between the two panels (interclass correlation coefficient, 0.97). The nostril width ratio was the most predictive of both internal and external rank scores (r = 0.76, p < 0.0001; and r = 0.81, p = 0.0003, respectively). The columellar angle was also highly predictive of both internal and external expert rank scores (r = 0.73, p < 0.0001; and r = 0.79, p = 0.0005, respectively). CONCLUSIONS: Experts are reliably able to subjectively rank patients according to the degree of nasal deformity. Measures of the columellar angle and the nostril width ratio vary in a linear fashion with the perceived deformity and may serve as independent and objective indicators of presurgical severity of unilateral cleft lip nasal deformity.