Five cases of cellulitis due to H influenzae type b in children are described. Cellulitis due to H influenzae type b should be treated in hospital using parenteral antibiotics in appropriate dosage to cross the blood brain barrier; it is recommended a lumbar puncture is performed in all cases of cellulitis in under two year olds, both to exclude meningitis and to allow the giving of steroids immediately prior to starting the first dose of antibiotics. Index cases and close contacts should be offered chemoprophylaxis to prevent spread of the organism. It seems likely that a vaccine against H influenzae b, effective in under two year olds, will become available in the next few years.