BACKGROUND The CardioMEMS heart failure system is a small sensor that is placed in a branch pulmonary artery for ambulatory monitoring of pulmonary artery pressures. CardioMEMS has been approved for use in the United States in patients with New York Heart Association (NYHA) class III heart failure and frequent hospitalizations. In this report we describe a patient who had hemoptysis after CardioMEMS implantation. Further, we discuss possible etiologies for the occurrence of hemoptysis and suggest strategies to minimize this risk. CASE REPORT The patient was a 79-year-old female with NYHA class III heart failure with non-ischemic cardiomyopathy (LVEF 40%) and chronic atrial fibrillation who was referred for CardioMEMS implantation. The procedure was completed uneventfully. The patient was transferred out of the procedure suite to the recovery area where she developed a slight cough approximately 20 minutes after the implantation. Within a few coughs the patient started having hemoptysis. She was transferred to the cardiac intensive care unit for observation. She was kept off warfarin and aspirin and her hemoptysis resolved 3 days later. While the exact etiology of hemoptysis in this patient was unclear, we felt that it may have been precipitated by a minor wire-induced distal branch pulmonary artery injury. CONCLUSIONS Our report discusses hemoptysis as a potential life-threatening complication of CardioMEMS sensor implantation while suggesting possible etiologies and avoidance strategies. As the utilization of this technology expands in the years to come, a more comprehensive national registry for surveillance of device related complications will be crucial.