The success of treatment aimed at improving manifestations of venous insufficiency appears today to be closely linked to a therapeutic impact on blood viscosity and the macrorheological parameters upon which it depends. This double-blind placebo-controlled trial of troxerutine was designed to evaluate changes during treatment in rheological abnormalities in 60 women with vulval varicosities and venous insufficiency of the lower limbs, half in the context of premenstrual syndrome and half in pregnant women from the 4th month on. Initial examination revealed no significant difference between the treated and control groups from a clinical and rheological standpoint in the gynecological and obstetric categories. Analysis of results showed that a high dose of troxerutine was associated with a very marked improvement in symptomatic parameters by the first month of treatment with a significant correlation between clinical criteria and rheological parameters in pregnant women as well as in those with a premenstrual syndrome. These data were confirmed by excellent acceptability as well as subjective assessment by patients after 4 months' treatment at the dosage of 4 g/d.