Despite great strides in our understanding and treatment of atrial fibrillation over the past decade or so, much remains to be learned.  Debate continues over the relative merits of rate versus rhythm control strategies.  More recently, even the optimal targets for rate control have come into question.  Specifically, the results of the RACE II trial support a more lenient rate control target compared to more traditional targets.  This paper will review the role elevated heart rates play in the morbidity associated with atrial fibrillation, tools available for rate control and their relative merits as well as the targets for rate control.