Cholinesterase inhibitors are prescribed in the treatment of mild to moderate Alzheimer's dementia. Little is known about the cardiac safety of these drugs. We present two different cases in which cardiac events occurred during the use of a cholinesterase inhibitor. The pathophysiology, the effects of these drugs on the heart, information about the reports of side effects in pharmacovigilance databases and known literature are discussed. Although cardiac risks of cholinesterase inhibitors seem small, we advise to monitor cardiac effects of cholinesterase inhibitors carefully in patients with existing cardiac disease, especially in those using concomitant drugs known to interact with the cardiac risks of cholinesterase inhibitors.