Lemon balm ( Melissa officinalis ), which belongs to the Lamiaceae family, is an herb with a citrus flavor, used widely for herbal tea due to its appetite and sleep improving properties. In this study, lemon balm was examined for α-glucosidase inhibition effects and suppression of blood glucose increases, which correlate with the prevention of diabetes. Cookies and cooked rice with added lemon balm were also evaluated for taste. The extract of lemon balm with hot water (lemon balm tea) was shown to have the highest activities of both of α-glucosidase inhibition and radical scavenging amongst the extracts of eight citrus-flavored herbs, namely lemon balm, lemon thyme, lemon verbena, lemon grass, lemon peel, orange blossom, bitter orange peel, and sweet orange peel. Rosmaric acid, a radical scavenger, occurred at higher levels in lemon balm than in the other herbs. The adsorption fraction of reverse-phase resin-applied lemon balm tea was suggested to contain α-glucosidase inhibitors. Lemon balm tea was shown to have a suppressive effect on the increase of blood glucose after ingestion of sucrose in mice. Cookies with added lemon balm leaf were evaluated by a taste test as having significantly superior flavor in comparison to cookies without added lemon balm leaf, although they were inferior in appearance (p<0. 05). Cooked rice with added lemon balm, carrot, and chicken received a high evaluation in a taste test