The prevalence of Diabetes mellitus has increased around the world in the last decade. Anyone with diabetes is at risk of diabetic eye complications. The aim of the study was to compare effects of standardized Ginkgo biloba (Ginkgo biloba L.) dry extract (Ex.Gb) with the placebo on the microcirculation lesions of the eye in randomized double-blind placebo-controlled trial. 44 patients with type 2 diabetes mellitus were randomized to Ex.Gb 160 mg per day or placebo, and were followed up for nine months. Dose of Ex.Gb was increased to 240 mg in next nine months. Total Antioxidant Status (TAS) of plasma was measured using the Trolox equivalent antioxidant capacity assay. Ophthalmologic examination was performed by the biomicroscopic method. Vascular, intravascular and perivascular alterations were evaluated, and total conjunctival index was calculated. Though the values of the total conjunctival index and its constituent decreased (P<0.05) during the study in Ex.Gb group, there were no significant differences between these parameters as compared with placebo group. Evaluation of plasma TAS showed gradually increment, although insignificant and very small, in Ex.Gb group. The significance of Ex.Gb on development of the alterations of eye microcirculation, especially in elder patients needs to be explored further.