The Lalonde Report was published in 1974, and was the first significant government report to suggest that health care services were not the most important determinant of health. After reviewing the evidence, the report suggested that there were four "health fields"--lifestyle, environment, health care organization, human biology--and that major improvements in health would result primarily from improvements in lifestyle, environment and our knowledge of human biology. Lalonde also indicated a broad understanding of the determinants of health in subsequent speeches. While the report was greeted sympathetically at the time, it did not have all that significant an impact in Canada. It was criticised on a number of grounds, in particular that it paid too much attention to lifestyle and too little attention to environment. Furthermore, because health is a provincial responsibility in Canada, while the report was a federal report, there was no mechanism readily available to implement the recommendations of the report. The report was nonetheless widely hailed outside Canada, and similar (and often better) reports were published in Britain, the USA, Sweden and elsewhere. The report remains a highly regarded contribution to the transformation in thinking about health that has occurred in the past decade.(ABSTRACT TRUNCATED AT 250 WORDS)