Statistical analysis of the relatiojnship between human perceptions and the physical characteristics of a sample of Japanese profiles led to the development of the Profile Aesthetic Index. The Profile Aesthetic Index is a composite of seven physical variables (five angles and two dis tances) measured on soft tissue profiles. The correlation between the index score and the mean rating score given by orthodontists and dental students was r = .80. Clinical validity of the Profile Aesthetic Index was examined by comparing the index scores before and after the surgical-orthodontic treatment of 50 patients. Potential uses and limitations of the index are discussed.