An attempt is made (1) to define adolescence as a biological phenomenon, (2) to describe the characteristics of the adolescent in Latin America, and (3) to identify the adolescent within certain social and cultural groups of specific Latin American countries. The perspective of the four-part monograph is entirely sociological, and the report is intended for use by secondary school teachers in Latin America for teacher-training programs. Part I discusses the adolescent personality and role in society; Part II treats the physical, mental, social, and personality growth of teenagers; Part III advances the importance of the secondary school in the adolescent's life; and, Part Iv suggests various methods and resources for further study of adolescence. There are tables of data and graphic charts included in the study, which is a compilation of lectures delivered by the author at the University of Buenos Aires, Argentina, during 1961. (DS)