Ivabradine is generally considered to be a safe drug with well-established and substantial benefits. Nevertheless, recently published results from the SIGNIFY trial suggest that ivabradine has rather inconsistent effects on cardiovascular outcomes. In addition, careful examination of all available data from ivabradine trials reveals signals of harm that have not yet been appropriately addressed, including a markedly increased incidence of atrial fibrillation and increased risk of cardiovascular events in patients with heart rates below 70 bpm. These concerns warrant consideration, since they could have implications for the future use of ivabradine.