Purpose: The objective was to assess knowledge related to sugars consumption and World Health Organization (WHO) sugars guideline among Canadian dietitians and other health professionals. Methods: A multiple-choice style survey was administered at Dietitians of Canada and Canadian Diabetes Association conferences in 2014. Results: The study showed that only 12% of the surveyed respondents (n = 335) in 2014 were able to correctly identify the amount of added sugars consumed by Canadians, whereas two-thirds overestimated this amount. About 10% of the respondents knew that the 10% guideline by WHO for free sugars was based on evidence related to dental caries. Registered dietitians had relatively better knowledge of Canadian sugars consumption (P = 0.003), but not of the WHO free sugars guideline compared with other surveyed health professionals such as medical doctors or nurses. Conclusions: Knowledge gaps existed among surveyed Canadian health professionals on topics related to sugars consumption and the WHO sugars guideline. Future research should focus on tools to support better communication of sugars guideline and consistent use of sugars terminology.