Background Limited employment opportunities for recently trained cardiac surgeons are deterring medical students from entering cardiac surgery residency programs. Given the lengthy training period and the aging of both the general population and currently practicing cardiac surgeons, this reduced enrollment raises concerns about the adequacy of the future cardiac surgery workforce. A workforce model was developed to explore the future need for cardiac surgeons in Canada. Methods A novel system dynamics model was developed to simulate the supply and demand for cardiac surgery in Canada between 2008 and 2030 to identify whether an excess or shortage of surgeons would exist. Several different scenarios were examined, including varying surgeon productivity, revascularization rates, and residency enrollment rates. Results The simulation results of various scenarios are presented. In the base case, a surgeon shortage is expected to develop by 2025, although this depends on surgeons' response to demand-supply gap changes. An alternative scenario in which residency enrollment directly relates to the presence of unemployed surgeons also projects substantial shortages after 2021. The model results indicate that if residency enrollment rates remain at the 2009 level an alarming shortage may develop soon, possibly reaching almost 50% of the Canadian cardiac surgical workforce. Conclusions These workforce model results project an eventual cardiac surgeon shortage in Canada. This study highlights the possibility of a crisis in cardiac surgery and emphasizes the urgency with which enrollment into cardiac surgery training programs and the employability of recently trained cardiac surgery graduates need to be addressed.