Several theories on the etio-pathogenesis and physio-pathology of hemorrhoids have been up to now proposed. From the fisio-pathological viewpoint, particular importance is retained by the vascular factor, which in its turn is influenced by mechanical and sphinceric factors, that impair the venous back-flow. In the evidence of an hemorrhoidal crisis, characterized by local oedema, pain and bleeding, the use of bioflavonoid drugs is deemed to be the first choice. We investigated the use of purified diosmin, given at a dose of two 450 mg tablets bid for the first 7 days, then at 1 tablet bid for up to 2 months, in a group of 66 patients suffering from primitive hemorrhoids of grade 1-4. Our results confirmed diosmin efficacy in decreasing both pain and bleeding: reduction rates of 79% and 67%, respectively, were reached in the first treatment week. In the second week, figures were 98% and 86%, respectively. Diosmin tolerability was excellent: this characteristic makes the drug very easy to handle by the general practitioner and also useful to the proctologist in the preparation of patient to further treatments.