Investigations of the physical properties of fruit before and after cooking and a sensory evaluation after cooking were conducted with 5 eggplant cultivars including ‘Yatakei’, a native strain of ‘Kamonasu’ in Nara. The moisture content and firmness were measured of flesh cubes of 2 × 2 × 2 cm before and after being either steamed or fried with salad oil. The fried flesh was then evaluated with respect to its taste quality and texture related to the oiliness. As the results, the total weight of flesh was increased by steaming and decreased by frying. The moisture content of flesh was highest in ‘Mizunasu’ and lowest in ‘Kurowashi’ before cooking. It was slightly increased in all cultivars and no significant differences among the 5 cultivars was observed after the steaming. In contrast, a marked decrease and a significant difference in the moisture content of flesh were noted in the 5 cultivars by frying. The moisture content of the fried flesh was higher in ‘Yatakei’ and ‘Kurowashi’ whereas they contained lower oil levels than the others. A significant negative relationship between the moisture and oil contents of fried flesh was found. Before cooking, the firmness of flesh was significantly different among the 5 cultivars, being highest in ‘Kurowashi’ and lowest in ‘Mizunasu’, and it was markedly reduced after cooking. It was highest in ‘Yatakei’ and lowest in ‘Senryonigo’ after steaming, but highest in ‘Mizunasu’ and lowest in ‘Senryonigo’ and ‘Shoyaonaga’ after frying. Sensory evaluation revealed a significant difference in the texture related to oiliness among cultivars, with higher levels of oiliness found in ‘Shoyaonaga’ and ‘Mizunasu’ compared to ‘Yatakei’. There was a strong relationship between the texture related to oiliness and the content of moisture or oil in the fried flesh.