Cardiac nuclear imaging is one of the most commonly used imaging methods today to investigate myocardial ischemia or viable tissue in patients with suspected coronary artery disease. There are many studies on extracardiac finding scans in these images taken as tomographic sections. However, there is no report in the literature regarding the extracardiac findings encountered during 18 Fluoro-2-Deoxyglucose (18F-FDG) cardiac Positron Emission Tmography (PET), which is a metabolic evaluation. In this case report, we discussed a case who presented with chest pain, had myocardial wall motion disorder but did not have significant coronary artery stenosis, and was diagnosed with incidental lung cancer on myocardial 18F-FDG PET imaging taken during cardiac evaluation.