Osteoporosis can be thought of as a disease of childhood with manifestations in the adult years. One strategy in prevention of osteoporosis is to maximize peak bone mass with interventions focused during the childhood and adolescent years, taking advantage of this unique window of opportunity to maximize bone mass accrual, maximize peak bone mass, and theoretically decrease fracture risk for life. Factors important in the development of peak bone mass in children are reviewed. Studies examining bone metabolism and bone density in children with juvenile rheumatoid arthritis (JRA) are summarized. There is much work to be done before the best treatments for the osteoporosis of JRA are defined. Optimizing calcium intake and physical activity, along with corticosteroid avoidance and control of disease activity, is sound management for children with JRA.