The intraosseous pressure in the femur and tibia near the knee and in the internal saphenous vein at knee level was measured in fifty-three patients with suspected knee lesions. There were four groups: with and without degenerative osteoarthritis and with and without aching rest pain of the knee region. Low intraosseous pressures were found in patients with neither osteoarthritis nor rest pain, and in half the patients with osteoarthritis but without rest pain. Low pressures were found in the tibia, but very high intraosseous pressures were found in the femur in most patients with osteoarthritis and rest pain. Patients with no osteoarthritis but with rest pain mostly had high pressures in both the tibia and the femur.