Both children and adolescents are frequently affected by low back pain--mainly when they are involved in sporting activities--but they rarely ask for medical help, because their symptoms are often mild and self-resolving. However, in the young patients who seek orthopaedic evaluation, especially in referral centres, there is a high incidence of organic causes of their back pain. Mechanical, developmental, inflammatory and tumoural or tumour-like disorders are the most frequent aetiologic factors. A diagnosis of psychosomatic back pain should be made only when all the other possible organic causes have been excluded. Rehabilitation is part of the treatment of low back disorders in children and adolescents. Postural low back pain is likely to be resolved by physical therapy alone. In other disorders that initially require medical, orthotic or surgical treatment, rehabilitation plays an important role either in combination with them or as a subsequent treatment.