INTRODUCTION: In Canada, aviators and seafarers are required to be medically fit by international and domestic standards to be issued a medical certificate by Transport Canada (TC). In the event of denial or restriction, individuals have the right to a review by an independent decision-maker with medical expertise/training in marine and/or aviation medicine. This paper presents the results of cases submitted to the Transportation Appeal Tribunal of Canada over 19 yr.METHODS: The Tribunal’s repository of medical records was searched and 112 adjudicated cases were reviewed.RESULTS: Since 2000, 55 (49%) cases were in the aviation sector and, since 2010, 57 (51%) cases were in the marine sector. The mean age of applicants was 49 and 54 yr for seafarers and pilots, respectively. Mental illness, cardiovascular disease, visual, and neurological disease were the most common reasons for a medical certificate restriction/denial. The Tribunal upheld the refusal to issue or renew a medical certificate in 89 (79%) cases and 23 (21%) cases were referred back to TC.CONCLUSIONS: Mental illness is the most frequent diagnosis that precipitates a request. The international literature is sparse on the number, causes, and results of the appeal process. Our findings and the application of the medical standards in Canada are generally comparable with those of the United Kingdom. It was not possible to make more than indirect comparisons to those of the United States.Brooks C, MacDonald C. Medical cases adjudicated by the Transportation Appeal Tribunal of Canada: 2000–2018. Aerosp Med Hum Perform. 2020; 91(2):79–85.