Pulmonary embolism causes pulmonary vascular obstruction and damages circulation, leading to death in serious cases. Various cases of thrombosis have been reported as adverse reactions after vaccination with COVID-19 vaccines, and reliable studies on thrombosis with thrombocytopenia syndrome (TTS) have been confirmed, especially for viral vector vaccines. However, the association with mRNA vaccines has not been proven. We report a case of pulmonary embolism and deep vein thrombosis that occurred after using mRNA COVID-19 vaccines (BNT162b2).