Myocardial gene transfer has become a routine tool to investigate the pathophysiology of cardiac diseases, although translation of gene transfer techniques into therapeutics has not come as quickly as many had hoped. In the field of cardiac arrhythmias, there is a great need for new therapeutic options. The current work reviews the use of gene transfer to evaluate cellular electrophysiology, the application of in vivo gene transfer to treat common arrhythmias, and the current problems in the field of cardiac gene therapy. Arrhythmia gene therapy is a field in its infancy, and future human applications are dependent on solutions to the problems discussed in this review.