Introduction: The purpose of this study was to quantify the frequency and timing of Canadians' Internet searches for information on modifying cancer prevention-related behavioural risk factors.

Methods: We used the Google AdWords Keyword tool to estimate the number of Internet searches in Canada from July 2010 to May 2011 for content associated with the keywords ''physical activity / exercise,'' ''healthy eating / weight loss'' and ''quit smoking.''

Results: For ''physical activity / exercise,'' 663 related keywords resulted in 117 951 699 searches. For ''healthy eating / weight loss,'' 687 related search terms yielded 98 277 954 searches. ''Quit smoking'' was associated with 759 related keywords with 31 688 973 searches. All search patterns noticeably peaked in January 2011.

Conclusion: Many Canadians are actively searching for information on the Internet to support health behaviour change associated with cancer prevention, especially during the month of January. To take advantage of this opportunity, key stakeholders in cancer prevention need to identify knowledge translation priorities and work with health agencies to develop evidence-based strategies to support Internet-facilitated behaviour change.