Ventricular arrhythmias are an important cause of death, and can also be a serious side effect of drugs. Computational models are becoming established as important research tools, alongside experimental work, for understanding the mechanisms that initiate and sustain these dangerous events. Advances in computer power have enabled large-scale simulations of cell and tissue electrophysiology, and advances in imaging have generated detailed models of cardiac anatomy. Active research areas include action potential propagation around an infarct, detailed modelling of drug effects in multi-scale models, low-voltage defibrillation and pipelines to establish patient-specific models of structure and function. Although computational power remains a bottleneck for high throughput simulations, it is probable that electrophysiological models will continue to become increasingly important tools.