The effect of skin grafts on the size of collagen fibrils in autografted human burn wounds was examined. In autografted burn wounds, the mean (+/- standard deviation) diameter of collagen fibrils was 61.16 +/- 15.18 nm, against 39.77 +/- 6.51 nm in ungrafted burn wounds. This result indicates that autografts (0.1 mm thick) promote the maturation of collagen in burn wounds.