Acute myocardial infarction (AMI) due to arthropod envenomation has rarely been reported in the literature. In the present report, we describe two cases who developed AMI following an arthropod bite. Coronary angiograms revealed normal coronary arteries in both patients. Both events were probably secondary to coronary artery thrombosis and/or coronary artery vasospasm. Both patients were subsequently found to be heterozygous for prothrombin mutation (G20210A). As a result, we recommend ruling out the possibility of hereditary thrombophilias in young patients with AMI developing after an arthropod bite.