Multiple chronic conditions (multimorbidity) are common among elderly patients; however, little is known about the specific effects of multimorbidity on health care utilization and health care costs. This article reviews empirical studies from the international literature that investigated the relationship between multiple chronic conditions and health care utilization (e.g. ambulatory care, stationary care, pharmacotherapy) and/or health care costs in elderly general populations. Although synthesis of studies was complicated, especially because of ambiguous definitions and measurements of multimorbidity, almost all studies observed a positive association of multimorbidity and utilization and costs. Many studies found that utilization and costs significantly increased with each additional chronic condition. In light of these findings coupled with the fear that current care arrangements may be inappropriate for many multimorbid patients, important implications for research and policy are presented and discussed.