We report an 81-year-old woman with multiple myeloma who developed acute cardiac injury after receiving bortezomib. The patient received weekly intravenous bortezomib. She developed shortness of breath and bilateral pedal edema on day 19. Electrocardiography showed no ST-T changes but the cardio-thoracic ratio was increased, the ejection fraction was decreased, the ventricular septum showed hypokinesis and mitral regurgitation was noted. We stopped bortezomib and started acute congestive heart failure treatment. ST-T changes were detected after the patient's condition improved. There was no evidence of coronary stenosis on CT angiography. Acute cardiac injury is rare during bortezomib administration, but patients should be monitored carefully during treatment.