Purpose The objective of this study was to explore Canadian rural‐urban differences in the use of primary and secondary preventive diagnostic services for acute myocardial infarction (AMI)—a condition that is amenable to primary health care prevention efforts. Methods We examined primary and secondary preventive care services utilized 2 years prior to a patient's first AMI in a cohort of 30,491 patients in Ontario, Canada, from 2010 to 2012. Using logistic regression, rural‐urban differences in lipid testing, glucose testing, stress testing, electrocardiograms, and echocardiograms in middle‐age and senior patients were examined. Findings The odds of rural patients receiving care for primary preventive screening were more than 50% lower than the odds for urban patients, with rural seniors being the most affected. Lipid testing: middle‐age OR 0.519 (95% CI, 0.469‐0.574), senior OR 0.422 (0.386‐0.460); glucose testing: middle‐age OR 0.471 (0.426‐0.521), senior OR 0.359 (0.328‐0.394). The odds of rural patients receiving secondary preventive diagnostic care were also lower than the odds for urban patients, but differences between the age groups were not as apparent. Stress testing: middle‐age OR 0.745 (95%CI, 0.642‐0.866), senior OR 0.726 (0.643‐0.820); electrocardiogram: middle‐age OR 0.815 (0.737‐0.901), senior OR 0.724 (0.659‐0.795); echocardiogram: middle‐age OR 0.755 (0.655‐0.869), senior OR 0.746 (0.681‐0.818). Conclusions Study results support ongoing concerns related to health care for rural Canadians by demonstrating underutilization of AMI preventive diagnostic care among rural patients. Rural seniors are most at risk. These results have implications for rural health care as well as seniors’ health policy in Canada.