Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 56 5 2018 05 20 351 354 EN Mohammad Mehdi Bagheri Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran. AND Department of Pediatrics, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran. Shokouh Arjmand Kerman Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran. Mohammad Hossein Torabinejad Department of Pediatrics, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran. Mina Behzadi Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran. 2016 12 24 2017 03 30 Kawasaki disease (KD) is a self-limited syndrome with serious heart complications, mostly seen in children of age 5-month to 4-year-old. KD needs to be diagnosed soon to start IVIG within 10 days of starting symptoms to lower heart complications to 5 folds. Our case, a 2-year-old boy presented with prolonged fever and pharyngeal erythema. In early evaluation, erythrocyte sedimentation rate (ESR) was elevated, and after that, Color Doppler echocardiography with suspicion for KD was performed and showed aneurysm and thrombosis formation in the left coronary artery (LCA). Hence, intravenous immunoglobulin (IVIG) was started for the patient concurrent with daily check of troponin I level. In this case report, we present remarkable echocardiographic findings of a patient with the delay in diagnosis of KD demonstrating an aneurysm and acute thrombus formation in LCA.    https://acta.tums.ac.ir/index.php/acta/article/view/6086 https://acta.tums.ac.ir/index.php/acta/article/download/6086/5102