Thermal maps of the lumbo-sacral and gluteal regions and of the lower limbs were obtained with telethermography in 30 subjects suffering from painful lumbo-sciatic syndromes in order to assess whether there were differences of thermal index between painful and opposite side, and to evaluate the telethermographic patterns of the irritative and deficitary forms. Among 25 patients with lumbo-sciatalgia in the irritative or early stage, 16 showed hypothermia of the affected side; in three of the five patients in the deficitary stage, hyperthermia of the affected side was observed while two did not show changes of the thermal gradient. The authors stress the importance of telethermography and suggest that this method, which is not costly, non-invasive and easily reproducible, should be used to complete diagnosis of and to monitor lumbo-sciatalgic syndromes.