OBJECTIVE: To examine immobilization stress-induced antioxidant defense alterations in rat kidney and the antioxidant effects of aqueous garlic extract in pre and post stress extract treatments. METHODS: Albino rats were treated with aqueous extract of garlic both before and 6 h of immobilization stress. Pro-oxidant eminence of rat kidney was assessed by determining the levels of glutathione, thiobarbituric acid reactive substances, aspartate aminotransferase, alanine aminotransferase, glucose, uric acid, alkaline phosphatase and antioxidant enzymes activities. RESULTS: In response to 6 h of immobilization stress, a significant rise in the level of kidney enzymes was recorded. However, antioxidant enzyme activities showed a sharp decline. CONCLUSIONS: The extract treatment before and after the stress reverted the activities of above mentioned enzymes towards their control values. Hence, garlic extract can be given as nutritional supplement for scavenging the free radicals generated in rat kidney.