To determine the effect of elastic compression stockings on deep venous hemodynamics we measured ambulatory venous pressure, venous refill time, maximum venous pressure with exercise, amplitude of venous pressure excursion, and duplex-derived common femoral and popliteal vein diameter and peak flow velocities with and without stockings in 10 healthy subjects and 16 patients with chronic deep venous insufficiency. The effects of below-knee and above-knee 30 to 40 torr and 40 to 50 torr gradient stockings were studied. Despite documentation of substantial stocking compressive effects by skin pressure measurements, neither below-knee or above-knee elastic compression stockings significantly improved ambulatory venous pressure, venous refill time, maximum venous pressure with exercise, or the amplitude of venous pressure excursion in healthy patients or in patients with deep venous insufficiency (p greater than 0.05). In patients with deep venous insufficiency stockings modestly increased popliteal vein diameter and flow velocity in the upright resting position (p less than 0.02). After tiptoe exercise without stockings deep venous peak flow velocity increased in healthy patients and in patients with deep venous insufficiency by a mean of 103% in the popliteal vein and 46% in the common femoral vein (p less than 0.01). With the application of elastic compression stockings only modest augmentation of deep venous flow velocity occurred in both groups above that seen in the bare leg after exercise. Thus elastic compression stockings did not improve deep venous hemodynamic measurements in patients with deep venous insufficiency. The beneficial effects of stockings in the treatment of deep venous insufficiency must relate to effects other than changes in deep venous hemodynamics.