In order to evaluate the correlation between the pressure exerted by compression stockings and a resulting improvement in venous hemodynamics, we carried out an open, randomized, prospective study on 22 patients (11 women and 11 men with an average age of 55.1 [10.3]) with chronic venous insufficiency (CVI) in the clinical stages C1-4, Ep, AS, Ap, PR. Dynamic strain gauge plethysmography was used to measure the acute effect on venous hemodynamics of 9 different compression stockings in compression class 2 (A-D). At the same time when venous function parameters were monitored, we also measured the pressure exerted by the compression stockings during rest and exercise. With all compression stockings the average resting pressure fulfilled in reclined patients the specifications for compression class 2 (25-35 mmHg at the ankle, CEN). The compression stockings lengthened venous refill time t0 in a statistically significant degree. The improvement in venous function was correlated with the ratios of maximal working pressure to resting pressure while standing (r = 0.97, p < 0.001). Compression stockings belonging to the same compression class vary in their acute effect on venous hemodynamics. The efficiency of the different therapeutic compression stockings was largely dependent on the amount of fabric stretch, which can be characterized in vivo with the ratio of maximum exerted pressure during movement to that while standing still. A knowledge of the hemodynamic effectivity of the various compression stockings allows the optimal stocking selection for each patient and his individual clinical situation.