This report of the National Center for Health Statistics presents national estimates of the prevalence of facial acne and other skin lesions among noninstitutionalized youths aged 12-17 years by age, race, sex, geographic region, population size of place of residence, family income, education of parent, overall health, indications of stress, selected health habits, and physiological development. The estimates are based on direct examination findings from the Health Examination Survey of 1966-70 among a national probability sample of 7,514 youths representative of the 22.7 million youths of the U.S. population. Major findings of the report include: (1) only about 28% of U.S. youths 12-17 years of age have essentially normal skin without significant scars or lesions; (2) facial acne is about as prevalent among girls as boys, but tends to start earlier and be less severe in girls; (3) of those affected, only 11% had seen a doctor; (4) white youths are slightly more likely than Negro youths to have moderate to severe facial acne, but less likely to have mild conditions. Extensive reference list, detailed tables of findings, statistical notes, glossary of terms, and survey instruments are included as appendixes. (MB)