Patients admitted for acute myocardial infarction that is not confirmed (non-AMI) have a prognosis only slightly better than that of patients with confirmed infarction. In a prospective, prognostic study of 158 patients with non-AMI the combination of exercise ECG and transient defects demonstrated at 201thallium scintigraphy identified low- and high-risk groups better than either examination alone. The purpose of a new, still ongoing study of non-AMI patients is to establish a relevant, cost-effective examination programme in order to arrive at a positive diagnosis in each non-AMI patient. Preliminary results of lung perfusion/ventilation scintigraphy suggest a rather low frequency of pulmonary embolism. Preliminary data of oesophageal scintigraphy suggest that about 25% of the non-AMI patients have abnormal mean transit times. The clinical significance of these data are discussed.