We report the case of a 75-year-old woman with new onset dyspnoea, hypotension, and right bundle branch block. Transthoracic echocardiography (TTE) showed a thrombus in the right pulmonary artery and acute pulmonary embolism was diagnosed. The patient immediately underwent fibrinolysis with tenecteplase, with prompt recovery of clinical conditions and ECG anomalies. Bedside TTE might be helpful for immediate diagnosis of massive PE needing rapid treatment by fibrinolysis.