This booklet examines the influence of television on children and adolescents in developing and developed nations, reviewing research on television's relationship to child health and development. The first section reviews specific research on such variables as number of television sets in use, amount of time spent watching television, age, sex, urban versus rural settings, and types of programs viewed. The second section examines the effects of television on child health, discussing frequent but minor disorders such as sleep disorders, effects on eyesight, and disturbed attention span and concentration, along with serious but exceptional disorders such as epilepsy, severe anxiety, and suicidal behavior. The third and fourth sections look at the positive and negative impact of television on intellectual development, language skills, social development, cognitive development, and socialization. The two last sections, respectively, review research on the impact of television on children in Asia and outline a Brazilian initiative to use television to educate young people, many of whom do not attend school regularly. An appendix describes the Training TV Viewers television program used in Brazil to educate people about the positive and negative influences of television. (MDM)