OBJECTIVE To summarize the available evidence concerning the occurrence and treatment of ventricular arrhythmias in patients supported with long-term ventricular assist devices (VADs). RESULTS Approximately one-third of left ventricular assist device-supported patients experience significant ventricular arrhythmias, with higher rates in certain patient subsets. Ventricular arrhythmias are associated with both increased mortality and morbidity in VAD-supported patients. Mechanical factors, myocardial fibrosis and alterations in cardiac myocyte physiology because of myocardial unloading are contributors to ventricular arrhythmias in this population. In the absence of definitive trials, current evidence supports implanted cardioverter defibrillators (ICDs) in long-term VAD patients to mitigate the risks associated with ventricular arrhythmias. Though antiarrhythmic therapies have limited efficacy, amelioration of inflow cannula contact with the endocardium and suction events or ablation of specific anatomic origins of ventricular arrhythmias, when present, are also efficacious in VAD-supported hearts. CONCLUSIONS As the application of long-term VAD support continues to grow, it will be increasingly important to clarify and target the mechanisms contributing to ventricular arrhythmias in this population. Prospective trials assessing the benefits of de-novo ICD placement, ablative strategies and other prophylactic and therapeutic interventions will be increasingly important to further improve the survival and quality of life among VAD-supported patients.