purpose: to compare the prevalence of demodex folliculorum on the eyelashes of patients with proliferative diabetic retinopathy and healthy voluntaries. methods: type 2 diabetic patients with proliferative retinopathy and age- and gender-matched healthy voluntaries (group control) underwent a slit lamp examination which three eyelashes containing cylindrical dandruff were removed from each lid by fine forceps. the lashes were dyed with fluorescein and the presence of demodex folliculorum was verified by direct visualization under a light microscope. the mites were recognized based on its morphology and peculiar movement. the results were expressed in "positive" when at least one mite on one lash was found and "negative" when no mite was identified. the chi-square test was used for comparing mites' presence in both groups. results: forty-two patients were included in each group. the age ranged from 50 to 60 years old, with a mean of 56.4 ± 5.2 years. the male:female ratio was 0.6:1. there was no statistically significant difference with regard to age and gender in both groups (p>0.05). demodex folliculorum was significantly more prevalent in diabetic patients (54.8%) than in control patients (38.1%) (p=0.048). conclusion: demodex folliculorum was more prevalent in diabetic patients than in healthy voluntaries, independently of gender and age.