The relationship between burn depth, healing time and the development of hypertrophic scarring (HTS) is well recognised by burn surgeons but is seldom mentioned in the published literature. We studied 337 children with scalds whose scars were monitored for up to 5 years. Overall HTS rates were found to be: under 10 days to healing=0%, 10-14 days=8%, 15-21 days=20%, 22-25 days=40%, 26-30 days=68% and over 30 days=92%. In the conservatively treated group the HTS rates are: under 10 days=0%, 10-14 days=2%, 15-21 days=20%, 22-25 days=28%, 26-30 days=75% and over 30 days=94%. If skin grafting is undertaken there is a much higher incidence of HTS in the 10-14 days group: 10-14 days=33%, 15-21 days=19%, 22-25 days=54%, 26-30 days=64% and over 30 days=88%. We conclude that there is a low risk of HTS formation in scalds healed before 21 days, and that surgery should be reserved for scalds likely to take more than 21 days to heal.