The root nodules of Cajanus cajan (L.) Millspaugh, a leguminous medicinal plant, was determined to contained high amount of ascorbic acid (AsA). A Glucose pool present in the root nodule might serve as precursor for AsA production. A symbiont was isolated from root nodules of the plant and was identified as a Rhizobium sp. based on biochemical and 16S rDNA based molecular phylogenetic approach. The symbiont produced large amount of AsA (640 µg/ml) from glucose supplemented basal medium. The production of AsA by the symbiont was increased to a greater extent than over control when the glucose (1.0 %) supplemented mineral medium was enriched with biotin (20 µg/100ml), thiamine hydrochloride (20 µg/100ml) and L-glutamic acid (0.2%). Our result supported the modern concept that AsA was also synthesized in root nodules of legume and refute the earlier concept that root nodules can not synthesize AsA.