Age-related changes in width (cheilion-cheilion) and height (subnasale-stomion) of the upper lip are studied in 2300 healthy Bulgarians, with ages ranging from three days to 102 years, for the needs of cheiloplasty in both surgery and fine arts. As shown by the results, at birth the upper lip in either gender appears to be one of the most developed organs of the human body, continuing to augment in size up to the eighth decade of life. In preschool age it terminates its intensive development, and in the puberty period it fails to exhibit the growth leap characteristic of the organism as a whole. Throughout the period of postnatal ontogeny, with the exception of early infancy, the lip in the male gender remains bigger, with the difference for height being rather markedly expressed during the ninth decade (3, 8 mm), and for width--thereafter (5.24 mm). The conclusion is reached that cheiloplasty may be undertaken regardless of the patient's age, during the early postnatal days inclusive, and the dimensions recorded for the age intervals being examined may serve as standard values.