This investigation proved that thermography is a reliable method of examination. When the difference of temperature in the legs reached 1 degree C or more, there was a correlation between clinical sciatica and the thermographic registration in 51 of 52 patients. As regards diagnosing the level, thermography is unreliable for distinguishing an L4/L5 syndrome from an S1 syndrome. In this investigation it was possible to correlate colder zones and the clinical syndrome in most patients. However, there is a large overlap between the dermatomes. When following up the results of autotraction no certain conclusions can be drawn, but among the patients with sciatica the decrease in temperature was greater in the group who clinically recovered.