The purpose of this study was to develop a standardized job description for dietitians using the DACUM technique. To examine the validity of job description through DACUM, dietitians were surveyed relative to importance, performance, and difficulty. The survey was conducted April 1-30, 2014. A total of 217 questionnaires were used in the analysis. The final developed job description for dietitians included six duties, 38 tasks, and 210 task elements. DACUM’s findings include six duties: nutrition management, food service operation management, hygiene safety management, community food and nutrition program management, organization management, and professionalism strengthening. There were 5.1 points regarding importance, 4.1 points regarding performance, 4.9 points regarding difficulty, and statistically significant differences (p<0.001). Dietitians responded that ‘nutrition management’ and ‘hygiene safety management’ were the most important. ‘Hygiene and safety management’ showed the highest performance, and ‘community food and nutrition program management’ and ‘professionalism strengthening'' showed the highest difficulty. Thus, it is considered that the job analysis results can be used to evaluate and improve the subjects’ training program. Dietitians’ jobs are subject to various environmental changes, such as demographic changes, health care system changes, and the development of the food industry, and thus, should be reviewed and analyzed periodically.