Therapy for cardiac arrhythmias is inadequate, based on current options. Gene therapy has shown tremendous potential to investigate pathophysiology and potential therapies for cardiac diseases. The current work reviews the possibilities for application of in vivo gene transfer to treatment of common arrhythmias, including vector selection, delivery technique, and data on in vivo gene transfer for rate control in atrial fibrillation and for pacemaking activity. Arrhythmia gene therapy is a field in its infancy, and future human applications are dependent on solutions to the problems discussed in this review.