Current guidelines emphasize the need for optimal medical therapy before implantation of cardiac devices (implantable cardioverter-defibrillator, cardiac resynchronization therapy). Our objective was to evaluate use of beta-blockers (BB) among patients with heart failure undergoing a cardiac device procedure. We used a large, multistate, managed-care database (January 2003 to December 2006) to identify adults admitted with an International Classification of Diseases, Ninth Revision (ICD-9) procedure code for cardiac device, continuous enrollment for 180 days before and 180 days after device procedure, and a primary or secondary ICD-9 diagnosis code for heart failure during that period. Our primary measures were use of BB before device procedure and changes after discharge. A total of 2766 beneficiaries (78.8% men; median age, 61 years) underwent a device procedure for primary prevention. The median number of days on BB therapy in the 90 days before device procedure was 46. Beneficiaries who did not have a pharmacy fill for BB during that time (n=925, 33.4%) were more elderly and had fewer antecedent outpatient visits with a cardiologist. There was a shift toward greater use of BB after device procedure; 83.4% had at least 1 pharmacy fill for a BB during follow-up. BB are underused before and after cardiac device procedures. There is a modest increase in use after the procedure. Strategies are required to ensure that patients are on optimal medical therapy before device therapy is selected.