From 1974 to 1983, inclusive, 274 children with acute suppurative osteoarticular infections were treated with antibiotic regimens that were shorter than usually recommended. The median duration of antibiotic treatment for acute suppurative arthritis caused by staphylococci, streptococci, Haemophilus influenzae type b, gram-negative cocci, or other gram-negative bacteria was 23, 16, 16, 15, and 22 days, respectively. For acute osteomyelitis caused by staphylococci, streptococci, H influenzae, or other gram-negative bacteria the median duration of antibiotic therapy was 24, 23, 17, and 22.5 days, respectively. Osteoarthritis usually had to be treated for about a month. 180 patients received large dosages of oral antimicrobials after clinical stabilisation with intravenous treatment, the median duration of intravenous therapy being about a week (range up to 7 weeks). 99% of patients underwent needle aspiration for diagnostic reasons. 36%, 71%, and 63% of the patients with acute suppurative arthritis, osteomyelitis, and osteoarthritis, respectively, underwent incision and drainage. Recurrence occurred in 4 patients with acute osteomyelitis (3.8% of cases). There was no recurrence of arthritis.