The authors set out to review Canadian medical workforce policies for 1993 to 2003 and assess if data existed in the 1990s that could have reversed the policy decision to curtail the supply of physicians from Canada's medical schools just as Canada was about to experience a developing shortage. The authors reviewed existing descriptive data sources regarding Canadian physician workforce size and activity from 1986 to 2003, including the Canadian Medical Association workforce database. The review indicated that a significant loss of physicians to retirement was imminent. Physician workforce productivity had started to fall by the early 1990s. Emigration to the United States had risen above traditional levels in the early 1990s and remained higher into the late 1990s. Despite these existing findings, an integrated adjustment to physician workforce policies taken in 1993-94 only occurred after 1999. The authors recommend that policy makers and managers must monitor the numbers from existing sources. To optimize these sources, planned data tracking and linkages are essential. The period in question demonstrated major disconnects in coordinating implementation, wherein subject experts monitoring data trends were not adequately utilized by policy makers. Finally, in complex systems with regional differences, policy decisions based on normative data are insufficient.