The troponin I (TnI) level is essential in the diagnosis of acute myocardial infarction, but may be elevated by other cardial and non-cardial causes. We report a 32-year-old pregnant woman admitted to hospital because of chest pain and dyspnoea. TnI levels were significantly elevated, although there was no suspicion of acute coronary syndrome or myocarditis, and supplementary diagnostics excluded pulmonary embolism. The TnI level was found to be falsely elevated due to immunoassay interference. We stress the need to be aware of the possibility of false positive TnI, especially during pregnancy.