We performed a cohort-based pharmacoepidemiologic study in order to evaluate the pattern of cephalosporin prescriptions in elderly inpatients in Korea. The Korea Elderly Pharmacoepidemiologic Cohort was composed of a geriatric population of beneficiaries of the Korea Medical Insurance Corporation residing in Busan in 1993. The cohort consisted of 23,649 members, comprising 15,221 women (64.4%) and 8428 men (35.6%). The study population for drug utilization review consisted of those cohort members who were admitted into hospitals during the period January 1993 through December 1994. The number of hospitalized patients was 4262, comprising 2631 women (61.7%) and 1681 men (38.3%). The trend of cephalosporin prescriptions over the 2-year period showed that the use of second and third generation cephalosporins increased relative to the use of first generation. The use of cephalosporins combined with other antibiotics was found to occur in 22.8% aminoglycosides (76.7%) and quinolones (17.1%) being the most common antibiotics combined with cephalosporins. Our result demonstrates an increase in the prescription of second and third generation cephalosporins in Korea, which has implications not only for the elderly population but also for the total population because of the impact on health care costs and the potential for the emergence of antimicrobial resistance.