From January 1974 to June 1980, a total of 46 patients were treated for infections involving permanent pacing systems. Demographic characteristics, types of infecting organisms, specific clinical features, significance of an infected foreign body and various medical and surgical treatment methods are described. Likely infecting organisms depend on the mode of presentation and the time course of the infection. Optimal treatment for the large majority of patients requires removal of the entire infected pacing system. In a subgroup of patients, a short course of antibiotic therapy followed by one stage surgery involving implantation of a new pacing system and concurrent explanation of the infected pacemaker was used safely with excellent results.