Farnsworth 100 Hue test was used to investigate color vision in 100 diabetic patients. Blue Yellow axis dyschromatopsia was found in 66.5% of patients. Such a dyschromatopsia precedes diabetic retinopathy in 55% of patients. Its frequency increased as a function of the increasing severity of diabetic retinopathy. On the other hand, 36% of the patients suffering from dyschromatopsia misinterpreted the self-monitoring (urine and blood) tests. These results suggest that the investigation of color vision may be a useful tool for the early screening of diabetic retinopathy particularly in self-monitoring patients.