Patients routinely seek physicians' guidance about diet and the relation between nutrition and the prevention and treatment of disease. However, the adequacy of nutrition instruction in undergraduate medical education is questionable. The purpose of this study was to investigate Canadian medical students' perceptions of and satisfaction with their education in nutrition. At 9 universities across Canada, a 23-item survey questionnaire was distributed in English and French to undergraduate medical students after at least 8 months of medical school. Overall, 9 of 17 universities participated in the survey, and 933 of the 3267 medical students approached completed the survey (response rate, 28.6%). Mean satisfaction with nutrition instruction received during medical school was 4.7 (+/-0.06) on a scale of 1-10, where 1 is very dissatisfied and 10 is very satisfied, and there were significant differences among schools (p < 0.0001). Students were comfortable in their ability to counsel patients regarding basic nutrition concepts and the role of nutrition in prevention of disease, but were much less comfortable discussing the role of nutrition in the treatment of disease and nutrient requirements across the lifecycle, and in identifying credible sources of nutrition information. Of the 933 respondents, 87.2% believe that their undergraduate program should dedicate more time to nutrition education. The amount of nutrition instruction correlated with student satisfaction (p < 0.0001), but varied among schools. A significant number of students are dissatisfied with the nutrition education they receive and their ability to provide relevant and appropriate nutrition counselling. This study paves the way for further discussions and development of strategies to improve nutrition education in medical schools in Canada.