Health care providers caring for adolescent pa tients are faced with problems unique to this age group due to their evolving developmental stages of growth. Serious problems with psychosocial as well as biological bases causing major morbidity and mor tality are encountered. Purely biomedical approaches and quality standards are likely to be inadequate. Age and developmental stage appropriate approaches to treatment and prevention are required, with atten tion to environmental stresses and risk-taking behav iors. Adolescent development, current hazards, and preventive strategies are reviewed.