Introduction 
Chemotherapy-induced Takotsubo (stress) cardiomyopathy (TC) have been
reported for several anticancer agents including antimetabolites,
fluoropyrimidines, and molecularly targeted agents(1). Some molecularly
targeted agents reportedly cause cardiovascular side effects, including
heart failure, arrhythmia (QT prolongation), and myocardial infarction
(2). The epidermal growth factor receptor (EGFR) inhibitors except
trastuzumab are known to cause less cardiotoxicity than BCR-ABL
inhibitors and vascular endothelial growth factor (VEGFR) inhibitors
(3). However, osimertinib has been reported more adverse cardiac events
than other EGFR inhibitors, including heart failure (4-6). While there
exist a few reports of osimertinib-induced heart failure in detail, none
have so far reported TC induced by osimertinib. Herein, we report a case
of TC caused by osimertinib.