PURPOSE: This observational, cross-sectional study evaluated healthy Caucasian Brazilian individuals' normal lip dimensions according to sex and age (20-50 years) using stereophotogrammetry. METHODS: A total of 130 individuals divided into four groups according to sex and age were analyzed using stereophotogrammetry. Ten linear lip, five angular lip, and three lip surface measurements (upper, lower, and total lip vermilion) were obtained. Comparisons were performed using two-way ANOVA. RESULTS: Mouth width, philtrum width, and lower lip cutaneous height were significantly greater in men than women. The upper lip height, upper lip cutaneous height, and average lower vermilion lip angle were significantly larger in men than women and increased with age (group), with medium or large effect sizes. A sex × group interaction was present for total vermilion height, upper vermilion height, total lip height, lower lip height, average upper vermilion lip angle, average Cupid's bow angle, mentolabial angle, and upper and total vermilion lip areas. When factors interact (sex/group), one affects the outcome of the other. CONCLUSIONS: Relevant linear lip measures were greater in men than women and increased with age in a mixed population from 20 to 50 years old. Thus, the lip and mouth are severly impacted by aging.