The purposes of the study were to identify knowledge and skill levels required for effective nutrition teachers and to compare perceived need and dietitians' self-evaluation of the knowledge and skills. A total of 60 knowledge statements and 70 skill statements associated with 11 job functional areas were specified through a literature review and expert panel reviews. A total of 457 dietitians working at school foodservices in Seoul and Gyeonggi province were surveyed using a self-administrated questionnaire and 148 responses were returned. Excluding responses with significant missing data, 142 responses were used for data analysis. In terms of knowledge, 'sanitation, food safety and employee safety (4.60)' category received the highest perceived need score, followed by 'nutrition education (4.56)' and 'nutrition counseling (4.45).' The knowledge category that received the highest self-evaluation was 'nutrition and menu management (3.66)' while the category that received the lowest self-evaluation was 'teaching practices (2.83).' In terms of skills, the highest perceived need was associated with 'nutrition education (4.49)', followed by 'sanitation, food safety and employee safety (4.46)' and 'nutrition counseling (4.39).' The dietitians rated their skills related to 'sanitation, food safety and employee safety (3.67)' the highest but their skills related to 'teaching practices (2.84)' the lowest. The dietitians' self-evaluated knowledge and skill scores were significantly lower than their perceived need of the knowledge and skills in all job functional areas (P < 0.001). A quadratic analysis based on the requirement and self-evaluation of the knowledge and skills revealed that priorities of the education programs targeting school nutrition teachers or students preparing to be a nutrition teacher should be placed on improving knowledge and skills related to nutrition education, nutrition counseling, teaching practices, sanitation and employee safety, and nutrition and menu management. Educational programs for nutrition teachers should be designed to decrease the gaps between the need and self-evaluation of the knowledge and skills for effective nutrition teachers. The findings of the study can be used to develop education materials for nutrition teachers. The knowledge and skills identified in the study should be updated and revised regularly to reflect changes in regulations and current practices in school foodservice programs.