Vitamin C content in the fruit of various cultivars of kiwifruit and other Actinidia species was estimated by determination of L-ascorbic acid and L-dehydroascorbic acid using ion-pair reversed-phase high-performance liquid chromatography. Fruit of A. deliciosa cv. Hayward, the most common commercially available cultivar, contained 65.5 mg/100 g fresh weight (FW) vitamin C. Vitamin C content in A. deliciosa fruit varied from 29 mg/100 g FW to 80 mg/100 g FW. In most cultivars of A. chinensis, vitamin C content in fruit was higher than that of Hayward. In particular, vitamin C content in cv. Sanuki Gold fruit reached more than 3-fold that of Hayward on a weight for weight basis. In A. argutafruit, there was wide variation in vitamin C content, with concentrations ranging from 37 to 185 mg/100 g FW. In cv. Gassan, Issai, and Mitsuko, vitamin C content of the fruit was much higher than that of Hayward. In A. arguta fruit, the ratio of L-ascorbic acid to total ascorbic acid tended to be higher than that of other species.