The aim of this study was to develop an aesthetic index for the evaluation of complete unilateral cleft lip and palate (UCLP) repair. The reproducibility and validity of this index were evaluated. A pilot study was devised, in which photographic slides of 50 subjects with UCLP were evaluated by seven orthodontic examiners on two separate occasions. After determining levels of agreement, the original index was modified for use in a clinical study. A field study was undertaken during an audit of cleft repair outcome in Perth, Western Australia. The subjects were graded using direct observation by two trained examiners. Standardized photographs of these subjects were taken at the same time. These were later graded by the same examiners independently on two separate occasions. Direct and indirect patient gradings could therefore be compared. A further field study involved the evaluation of the photographic slides of the original 50 subjects by 22 cleft surgeons. Reproducibility was determined by calculation of weighted kappa statistics. The intra-examiner agreement ranged from moderate to good and inter-examiner agreement from fair to good. Comparison of direct and indirect aesthetic evaluation revealed that the agreement was moderate to good, and no significant systematic bias existed. The new index offers advantages in simplicity and flexibility. Its reproducibility compares favourably with other aesthetic indices, and is not affected by the subject's age.