The objective of this study is to describe demographic and diagnostic factors which differ between recipients of single and dual chamber cardiac pacemakers. Characteristics of hospitalized patients receiving initial pacemaker implantation were determined using a multi-state inpatient discharge database. Logistic modeling was used to determine factors significantly associated with single verses dual chamber pacemakers. An estimated 51,375 single chamber and 69,897 dual chamber pacemakers were initially implanted in U.S. community hospitals in 1992. Analysis revealed significant association between single chamber pacemaker implantation and increasing patient age, even after controlling for diagnostic factors. Pacemaker recipients residing in lower income areas were also more likely to receive single chamber devices. Differences in the choice of pacemaker type implanted in Americans may be influenced by factors other than the medical indications for these devices. Examination of those factors will be important if the most appropriate use of medical technology is to be made.