Evidence suggests that newly licensed physicians are not adequately prepared to prescribe medications safely. There is currently no national pre-licensure prescribing competency assessment required in North America. This study’s purpose was to survey Canadian medical school leaders for their interest in and perceived need for a nation-wide prescribing assessment for final year medical students. Method In spring of 2015, surveys were disseminated online to medical education leaders in all 17 Canadian medical schools. The survey included questions on perceived medication prescribing competency in medical schools, and interest in integration of a national assessment into medical school curricula and licensing. Results 372 (34.6 %) faculty from all 17 Canadian medical schools responded. 277 (74.5%) respondents were residency directors, 33 (8.9%) vice deans of medical education or equivalent, and 62 (16.7%) clerkship coordinators. Faculty judged 23.4% (SD 22.9%) of their own graduates’ prescribing knowledge to be unsatisfactory and 131 (44.8%) felt obligated to provide close supervision to more than a third of their new residents due to prescribing concerns. 239 (73.0%) believed that an assessment process would improve their graduates’ quality, 262 (80.4%) thought it should be incorporated into their medical school curricula and 248 (76.0%) into the national licensing process. Except in regards to close supervision due to concerns, there were no significant differences between schools’ responses. Conclusions Amongst Canadian medical school leadership, there is a perceived inadequacy in medical student prescribing competency as well as support for a standardized prescribing competency assessment in curricula and licensing processes.