We studied the effects of a silicone gel bandage that was worn for at least 12 hours daily on the resolution of hypertrophic burn scar. In a second cohort, the prevention of hypertrophic scar formation in fresh surgical incisions by this bandage was also evaluated. In 19 patients with hypertrophic burn scars, elasticity of the scars was quantitated serially with the use of an elastometer. An adjacent or mirror-image hypertrophic burn scar served as a control. Scar elasticity was increased after both 1 and 2 months compared with that in controls. There was corresponding improvement clinically that persisted for at least 6 months. In the other cohort, scar volume changes in 21 surgical incisions were measured before and after 1 and 2 months. Gel-treated incisions gained less volume than control incisions after both intervals. Clinical assessment corroborated this quantitative demonstration of a decrement in scar volume. We concluded that topical silicone gel is efficacious, both in the prevention and in the treatment of hypertrophic scar.