Seventy-three children, who were admitted to hospital during the period 1965-1976 with osteomyelitis or septic arthritis, were included in a retrospective study as well as a clinical and radiological follow-up. Ten cases of osteomyelitis occurred during the neonatal period and about half of the cases of osteomyelitis and septic arthritis occurred before the age of 2 years. Staph. aureus was the dominating pathogen isolated and half of the strains were penicillin-resistant. The group of children with osteomyelitis who were given early treatment, i.e. within 1 week, against penicillin-resistant Staph, aureus had a higher clinical cure rate after 1 month (0.01 < P < 0.025) compared with the rest of the children. Five children developed recurrent or chronic osteomyelitis. An early follow-up in 69 children 1-11 years after the disease showed that none had any complaints or invalidity. However, one patient with neonatal septic arthritis presented severe dysplasia and subluxation of the hip and four children with osteomyelitis had severe, but asymptomatic, radiological changes.