Phenobarbitone, is a barbiturate with soporific, sedative and hypnotic properties and most widely used as anticonvulsant worldwide. This study investigated the effect of administration of ascorbic acid on phenobarbitone induced renal and hepatic toxicity. For the study, twenty four adult Wister rats were randomized into three groups of 8 rats each. The rats in first group (PV) were given phenobarbitone (15mg/kg orally) along with vitamin C (12.5mg/kg); the second group (P) were given phenobarbitone (15mg/kg orally) while the third group (C) were made the control and was given distilled water (1ml/200g). The treatments were given at 12hrs, 24hrs, 48hrs, 72hrs and 96hrs. At the end of the treatment period, the rats were sacrificed and biochemical assays were carried out on the plasma, kidney and liver tissues. The result showed that there was significant increase in the level of thiobarbituric acid reactive substances (TBARS), uric acid, catalase and aspartate aminotransferase (AST) in the plasma; there was increase in the level of TBARS and catalase in liver and kidney while Liver AST and kidney uric acid were reduced. All these changes were restored in animal treated with phenobarbitone and ascorbic acid. Hence, ascorbic acid may help to attenuate the hepatic and renal toxicity effect of phenobarbitone.