Spinal stenosisis narrowing of spinal, subarticular and neural canal by different reasons. Clinical complatints are the result of nerve and blood vessels impingement due to narrowing. The pathogenesis of neurogenic calaudication is unclear. According to some investigators, it is due to reduced blood flow to nerve roots, on the otherhand some other investigators believe that to be associated with compression of nerve roots. Conservativemanagement of spinal stenosis and its success in under debate. This includes lumbostat corset, resting, avoiding heavy working, NSAID and physical therapy. Surgical treatment of spinal stenosis include decompression of dural sac and nerve roots. In this study we evaluated the effect of physical therapy on physical examination findings and neurogenic claudication (pain-free walking distance). Lumbar spinal series on a four-viex, Ct scan and laboratory estimates were obtained. Pain on motion and resting pain, lumbar functional capacity, neurologic findings and neurogenic claudication distance were evaluated before and after treatment. Neurogenic claudication distance was measured on a treadmill with a speed 3 km/h and a slope 0%. In all patients taking physical therapy increase in pain-free walking distance, decrease  in pain on motion and resting pain and improvement of activities of daily living, lumbar functional capacity and neurologic findings were noted. The result of this study confirm the effect of physical therapy on pain in lumbar spinal stenosis, functional capacity, neurologic findings and neurogenic claudication. Physical therapy, besides its symptomatic effects, decreases spinal nerve root compression or ischemila, and so it increases neurogenenic cladication distance