The therapeutic efficiency of the Ginkgo biloba extract was estimated in a double-blind trial, during a 6 months period, in 29 diabetic subjects with an early diabetic retinopathy evidenced by angiography, and associated with a blue-yellow dyschromatopsia. The functional criterion was the color vision evolution, studied by the Desaturated Panel D-15 and the 100-Hue Farnsworth test at the beginning of the trial and 6 months later. An improvement tendency was evidenced in subjects treated by Ginkgo biloba extract, and an aggravation in subjects with placebo, this improvement being statistically significative with the Desaturated Panel D-15 among subjects without retinal ischemia. These clinical results on visual function corroborate the pharmacological actions of Ginkgo biloba extract on diabetic retina.