Bone mass is primarily genetically determined, but exogenous factors also play a major role. The prevention of osteoporosis can start from childhood, and optimal achievement of peak bone mass during childhood and adolescence is important in order to minimize the future risk of fracture. Chronic inflammatory diseases can have a detrimental effect on bone mass by means of several mechanisms. Different diagnostic methods for detection and monitoring of osteoporosis are in use or under investigation. The role of calcium and vitamin D supplementation for the prevention and treatment of osteoporosis associated with paediatric rheumatic diseases remains to be established. New treatments such as bisphosphonates and calcitonin are now available, although their use for paediatric patients has been limited.