Limited information exists on grocery shoppers' perceptions and use of Canada's Food Guide to Healthy Eating. The main objective of this study was to examine grocery shoppers' perceptions and use of the food guide in London, Ontario. The guide tearsheet and a self-administered questionnaire about food-buying practices were distributed to 2,000 food shoppers in ten London supermarkets. The response rate was 572 of 2,000 shoppers, or 29%; detailed results are reported in a separate paper. Four months later, a follow-up survey on the perceptions and use of the food guide was conducted through the use of a mailed questionnaire. (Both questionnaires had been pretested.) The response rate to the follow-up survey was 21% (118 of 572 participants). This survey revealed that 79% found the tearsheet useful or very useful. A majority indicated they would recommend its use to others. Over 75% reported awareness of the messages and almost two-thirds indicated that they had made some changes in their eating habits. About 40% provided helpful suggestions for revisions of the guide. The information obtained from this study will help health educators better understand shoppers' perceptions about the usefulness of Canada's Food Guide to Healthy Eating. The guide must be made more accessible, and shoppers' concerns about healthy food choices must be addressed.