Serial retinal photographs have been taken of a 14-year-old girl with long-standing, poorly controlled diabetes mellitus who presented with severe hypercholesterolemia. Selective fluorescence contrast photography revealed masses of dilated hairpin capillary loops in the retina. Over a period of 8 months of strict diabetic control the retinal vasculature returned to normal. The findings are discussed with reference to the origin and reversibility of retinal vascular changes in diabetes.