Abstract Background: Complications after surgical procedures in patients with cardiac implantable electronic devices (CIED) are an emerging problem due to an increasing number of such procedures and aging of the population, which consequently increases the frequency of comorbidities. Objective: To identify the rates of postoperative complications, mortality, and hospital readmissions, and evaluate the risk factors for the occurrence of these events. Methods: Prospective and unicentric study that included all individuals undergoing CIED surgical procedures from February to August 2011. The patients were distributed by type of procedure into the following groups: initial implantations (cohort 1), generator exchange (cohort 2), and lead-related procedures (cohort 3). The outcomes were evaluated by an independent committee. Univariate and multivariate analyses assessed the risk factors, and the Kaplan-Meier method was used for survival analysis. Results: A total of 713 patients were included in the study and distributed as follows: 333 in cohort 1, 304 in cohort 2, and 76 in cohort 3. Postoperative complications were detected in 7.5%, 1.6%, and 11.8% of the patients in cohorts 1, 2, and 3, respectively (p = 0.014). During a 6-month follow-up, there were 58 (8.1%) deaths and 75 (10.5%) hospital readmissions. Predictors of hospital readmission included the use of implantable cardioverter-defibrillators (odds ratio [OR] = 4.2), functional class III­-IV (OR = 1.8), and warfarin administration (OR = 1.9). Predictors of mortality included age over 80 years (OR = 2.4), ventricular dysfunction (OR = 2.2), functional class III-IV (OR = 3.3), and warfarin administration (OR = 2.3). Conclusions: Postoperative complications, hospital readmissions, and deaths occurred frequently and were strongly related to the type of procedure performed, type of CIED, and severity of the patient's underlying heart disease.