A major problem in patients surviving thermal injury is the development of hypertrophic burn scars. The current study was performed to determine the factors associated with an increased risk of the development of hypertrophic burn scars. Fifty-nine children (mean age, 3 years; mean TBSA, 14%) and 41 adults (mean age, 37; mean TBSA, 21%) followed from 9 to 18 months formed the study group. The location as well as time required for the burns to heal were recorded in addition to the age and race of the patients. Sixty-three (26%) of the 245 burn areas, in these 100 patients, became hypertrophic. No correlation between patient age and the development of wound problems was found. Blacks had more wound problems than others, if the burn wound took longer than 10 to 14 days to heal. The most important indicator of whether wound problems would occur, in our series, was the time required for the burn to heal. If the burn wound healed between 14 and 21 days then one third of the anatomic sites became hypertrophic; if the burn wound healed after 21 days then 78% of the burn sites developed hypertrophic scars. Based upon these results we have developed a selective, individualized protocol for the use of prophylactic pressure therapy in patients with spontaneously healing burn wounds.