In claudicants with arteriosclerosis obliterans admitted for vascular surgery, Buerger's test was compared with other indicators of lower limb ischaemia. Rest pain, gangrene, trophic changes, and chronic erythromelia were significantly commoner and more distal pulses were absent in Buerger positive limbs. Doppler and transcutaneous oxygen pressures and indices were significantly lower in Buerger positive legs. Significantly more occlusions were noted on arteriography in arteries distal to the adductor hiatus in the Buerger positive group. Buerger's test is a useful adjunct to routine peripheral vascular assessment and, if positive, suggests more severe ischaemia with distal limb artery involvement.