Oxerutins (Venoruton) and troxerutin (CAS 7085-55-4) are both mixtures of O-(beta-hydroxyethyl)-rutosides used for the treatment of chronic venous insufficiency. As di-O-(beta-hydroxyethyl)-rutosides and 7-mono-O-(beta-hydroxyethyl)-rutoside were found to be more active with regard to free radical scavenging compared to tri-O-(beta-hydroxyethyl)-rutoside the aim of this study was to compare oxerutins and troxerutin clinically. 12 female, post-menopausal patients with chronic venous insufficiency grade II participated in this double-blind study with random allocation to the treatment groups. They received 900 mg/day oxerutins or troxerutin for 12 weeks and were observed for 4 further weeks without treatment. Leg volumes (water displacement) and subjective symptoms (VAS, visual analogue scale) were evaluated before and following 2, 4, 8, 12 and 16 weeks. Both treatments were active in reducing leg volumes and in ameliorating subjective symptoms (mean volume reduction -167 +/- 157 ml x week). Volume reduction totalled to -261 +/- 154.2 ml x week for oxerutins and -73.2 +/- 97.1 ml x week for troxerutin. The difference is statistically significant (p = 0.04). The findings with subjective symptoms were in good accordance to the objective volume measurement. Oxerutins revealed a remarkable carry over effect.