From January, 1974, to December, 1983, 75 patients with infections related to permanent pacemakers were successfully treated. Demographic characterization, mode of presentation, types of infecting organisms, potential predisposing factors, significance of a retained infected pacemaker lead, and various medical and surgical treatment methods were analyzed. Likely infecting organisms depended on the mode of presentation and the time of the infection. Dermatologic diseases accounted for a significant number of secondary infections. Removal of the entire infected pacing system was required for eradication of infection in 74 of 75 patients. In 31 patients, the infected system was removed at the same time that the new system was implanted. In 26 patients, a two-stage procedure was used that included a period of temporary pacing between explantation of the old system and implantation of the new. No difference in complications or incidence of reinfection was found between these two groups. Infections occurring within 2 weeks after operation accounted for 15% of the cases. In these patients, Staphylococcus aureus was the most common organism. In patients with later infections, Staphylococcus epidermidis was the most common.