OBJECTIVE To describe the clinical features, natural history and response to treatment of coronary vasospasm associated with eosinophilia. METHODS Two patients with eosinophilia who had recurrent acute coronary events due to multi-vessel coronary artery spasm are described. The clinical presentation and outcomes of these 2 patients and 17 additional cases of eosinophilia and coronary artery vasospasm identified on a systematic literature review are presented. RESULTS Patients were usually admitted because of repeated episodes of angina at rest and raised plasma markers of myocyte necrosis. Dynamic ST elevation was observed in 15 (83%) patients. Coronary angiography was performed in all patients. Spontaneous (n=7) or provoked (n=8) coronary artery spasm, which was usually multi-focal, was observed in 15 (83%) patients. Symptoms often continued despite high dose vasodilators but responded well to prednisone. Recurrent coronary events were frequent, and included sudden death (n=4), resuscitated cardiac arrest (n=2), myocardial infarction (n=10) and unstable angina (n=11). Recurrent events were more frequent when not taking compared to when taking prednisone (4.2 versus 0.4 events/year, p=0.002, hazard ratio 11, 95% confidence interval 2.4-50). CONCLUSIONS Published case reports suggest that coronary vasospasm associated with eosinophilia responds poorly to conventional vasodilator treatment and the risk of recurrent coronary events is high. Most patients respond to treatment which suppresses the eosinophilia.