The objective of this preliminary study was to apply the theory of planned behavior to explain dietitians' intentions to promote whole-grain foods. Surveys were mailed to a random national sample of registered dietitians to assess knowledge and attitudinal, normative, and control beliefs regarding intention to promote whole-grain foods, with a 39% return rate (n=776, with 628 usable surveys from those working in direct patient care). About half of the respondents had a master's degree, and 58% had substantial experience in the dietetics field. The theory of planned behavior explained intention to promote whole grains to a moderate extent (df=3, F=74.5, R2=0.278, P<.001). Most were positive about the health benefits, and few perceived barriers to promotion. However, many had low levels of knowledge and self-efficacy regarding ability to help clients consume more whole-grain foods. Continuing education for dietitians should use strategies that enhance self-efficacy regarding ability to promote whole-grain foods.