Ivabradine, acting on the funny channel (If) in the sino-atrial node, reduces myocardial oxygen demand without inducing hypotension. It was developed as a specific bradycardic agent in the 1980s, avoiding the adverse effects of more traditional antianginal agents (beta-blockers and calcium channel antagonists). This has seen significant interest in this first-in-class treatment, and is perceived as a promising drug in the management of ischaemic heart disease and heart failure. There has been much clinical research conducted exploring its role in these fields, to try to elucidate potential benefits and target patient group. The side effect profile of ivabradine ensures it is well tolerated, and consistently leads to a reduction in heart rate. This review discusses the drug development and trial data in ischaemic heart disease and chronic left ventricular systolic dysfunction. Key clinical trials and observational studies are discussed in depth to examine potential explanations of unexpected or diverging results. The emerging role of ivabradine in acute decompensated heart failure is explored with recent trial data, providing a potential novel treatment avenue in this difficult to manage patient cohort. The role of intravenous ivabradine, as a beneficial tool in the acute hospital setting, when oral medication is not ideal, or where fast onset of action is required, in cardiac computerised tomography for example, is also discussed. Future directions for research are highlighted, including options for further elucidating unexplained results from previous studies.