No previous study has examined the differences in treatments and outcomes after acute myocardial infarction (AMI) between patients with and without rheumatoid arthritis (RA) in a setting where coronary reperfusion therapy was readily available. This study aimed to examine whether coexisting RA affected likelihood of receiving coronary reperfusion therapy and in-hospital mortality among AMI patients in a Japanese nationwide setting where coronary reperfusion therapy was readily available. Using the Diagnosis Procedure Combination database, we retrospectively identified patients admitted with AMI between 2010 and 2014 and created a matched-pair cohort of patients with and without RA based on age, sex, hospital, and admission year at a maximum ratio of 1:5. We performed multivariable logistic regression analyses for associations of RA with likelihood of coronary reperfusion therapy and 30-day in-hospital mortality. There were no significant differences between the RA group (n = 938) and non-RA group (n = 3839) in the proportions of patients receiving coronary reperfusion therapy (on the day of admission 75.8% vs. 77.2%, P = 0.364; during hospitalization 87.1% vs. 87.3%, P = 0.913) and 30-day in-hospital mortality (5.9% vs. 5.9%, P = 1.000). Multivariable logistic regression analyses showed that RA was not significantly associated with either likelihood of receiving coronary reperfusion therapy during hospitalization (odds ratio 1.02; 95% confidence interval 0.82-1.27; P = 0.837) or 30-day in-hospital mortality (odds ratio 1.16; 95% confidence interval 0.81-1.65; P = 0.419). Coexisting RA did not affect likelihood of receiving coronary reperfusion therapy or in-hospital mortality among AMI patients in a setting where reperfusion therapy was readily available.