This is a timely, concise, eminently practical, thoughtfully, even tenderly, written 28 page report of a recent WHO Expert Committee meeting on the health problems of adolescence. The members and the consultants to the Committee deftly summarize the major worldwide trends affecting our adolescent population. The size of this population is staggering; in the age group 15-19 years alone there are already 300 million adolescents in the world, and there seems every likelihood that these numbers will increase rapidly during the next decade.