Coronary artery spasm has rarely been observed in the transplanted, denervated heart. We report two patients who had coronary artery spasm after orthotopic heart transplantation that was documented by coronary angiography while ECG and Holter monitoring showed ischemic changes. Both patients were treated with calcium antagonists with no further evidence of this complication; however, one patient died suddenly at home after calcium antagonists were arbitrarily withdrawn. We believe that coronary artery spasm in heart transplant recipients may occur more frequently than expected. Careful monitoring of 24-hour ECG should be considered routinely in the follow-up of such patients, and when coronary spasm occurs it should be aggressively treated.