BACKGROUND Infections following cardiovascular implantable electronic device (CIED) procedures, including pacemaker and implantable cardioverter-defibrillators, are devastating and costly. Preimplantation prophylactic antimicrobials are effective for reducing postprocedural infections. However, routine postprocedural antimicrobials are not associated with improved outcomes, and they may be harmful. Thus, we sought to characterize antimicrobial use patterns following CIED procedures. DESIGN All patients who underwent CIED procedures from October 1, 2007 to September 30, 2013 and had procedural information entered into the VA Clinical Assessment Reporting and Tracking (CART) software program were included in this study. All antibiotic prescriptions lasting more than 24 hours following device implantation or revision were identified using pharmacy databases, and postprocedural antibiotic use lasting more than 24 hours was characterized. RESULTS In total, 3,712 CIED procedures were performed at 34 VA facilities on 3,570 patients with a mean age of 71.7 years (standard deviation [SD], 11.1 years), 98.4% of whom were male. Postprocedural antibiotics >24 hours were prescribed following 1,579 of 3,712 CIED procedures (42.5%). The median duration of therapy was 5 days (interquartile range [IQR], 3-7 days). The most commonly prescribed antibiotic was cephalexin (1,152 of 1,579; 72.9%), followed by doxycycline (118 of 1,579; 7.47%) and ciprofloxacin (93 of 1,579; 5.9%). Vancomycin was used in 73 of 1,579 prescriptions (4.62%). Among the highest quartile of procedural volume, prescribing practices varied considerably, ranging from 3.2% to 77.6%. CONCLUSIONS Nearly 1 in 2 patients received prolonged postprocedural antimicrobial therapy following CIED procedures, and the rate of postprocedural antimicrobial therapy use varied considerably by facility. Given the lack of demonstrated benefit of routine prolonged antimicrobial therapy following CIED procedures, antimicrobial use following cardiac device interventions may be a potential target for quality improvement programs and antimicrobial stewardship. Infect Control Hosp Epidemiol 2016;37:1005-1011.