Yaksun, a medicinal diet, has been traditionally prepared and applied (based on theories in oriental medicine) for the modulation of disease symptoms and signs. However, restaurants that serve and claim Yaksun mainly focus on stamina foods. A consistent definition of Yaksun has not been provided, which can confuse the public interpretation of Yaksun. The purpose of this study was to investigate the perception of Yaksun in Korean adults living in Seoul, Gyeonggi, and Chungbuk regions. Among the participants (M=55, F=168, 25y), only 10.4% understood the definition of Yaksun (mainly through the broadcast media). The frequency of Yaksun consumed when eating out was 2~3 times per month in 50.2% of participants. The main reason for choosing a Yaksun menu (46.3% of participants) when eating out was for health. The mean satisfaction score of Yaksun was $3.5{pm}0.8$ on the five point Likert scale. Participants highly agreed ($3.8{pm}0.8$) that Yaksun is composed of nutritious foods combined with oriental medicinal herbs for the treatment of disease, which was significantly higher in groups with learning experience on Yaksun (p<0.05). Interestingly, participants showed neutral to the description, that a diet without oriental medicinal herbs is not Yaksun ($3.1{pm}1.0$), which was significantly different between genders (p<0.05). Men recognized more than women that Yaksun should be based on oriental medical theory (p<0.05) and should be prepared for the prevention or treatment of diseases (p<0.05). In conclusion, the concept and terminology of Yaksun need to be defined and publicized in modern diet.