In this study levodopa was chosen as an agent that might ameliorate the clinical manifestations of paralysis induced by air embolism because of reported effects of this drug on muscle spasticity and locomotion. In order to induce air embolism, the aorta of rats was cannulated chronically. Fifteen days later, after full recovery of the animals, air was administered through the chronic cannula into the descending aorta of each rat (0.35 ml. of air per 100 Gm. during 4 seconds). The paralysis of both hind legs was observed one to 10 minutes later. Only animals that had total paralysis of both hind legs, without any sensation, were used in the experiments. levodopa was administered 2 minutes after experimentally induced paralysis. The levodopa treatment was repeated every day for 6 days. After 6 days, six levodopa-treated (intraperitoneally) animals in a group of eight and ten levodopa-treated (intra-arterially) animals in a group of 12 recovered fully from the paralysis. Only three animals in a group of 13 (untreated) or two animals in 12 (solvent administration) recovered without the levodopa treatment.