When I was a medical student, there were few lectures on public health at our university and such was true at most. The focus was on the treatment of individual patients with limited regard for the problems of the community. But as time has passed, there has been increasing concern about the population as a whole and approaches that might be appropriate for prevention of both acute and chronic diseases, for containing the spread of infection and for fostering healthy lifestyles. Many disciplines are involved but epidemiology, being the primary discipline of public health, lends itself well to serving as a common platform in joining all the disciplinary fields. Such was the case with the smallpox eradication program. The lessons learned from this experience are very relevant to current and future issues in public health.This is undoubtedly the most exciting time in history to enter the field of public health—so much is changing and so many new opportunities are presenting as the importance of population-based public health is increasingly perceived by governments, universities, and the community as a whole. The experience of working on the eradication of smallpox was a major development in my career as it was for many colleagues who served with me. I am pleased to be able to share this experience with a new generation, which faces both enormous challenges and opportunities in disease control and health promotion.