To study the natural history of acute sciatica, 208 patients with obvious symptoms and signs of a lumbar radiculopathy (L5 and S1) were examined within 14 days of onset. A concomitant double-blind investigation of the effect of the nonsteroidal anti-inflammatory drug piroxicam was performed. The results measured by visual analog scale and Roland's functional tests showed a satisfactory improvement throughout the 4 weeks of observation. The piroxicam-treated group had same results as the control group. Based on questionnaires at months 3 and 12 approximately 30% of the patients still complained about back trouble and 19.5% were out of work after 1 year. Four patients underwent surgery during this period.