Physicians often make clinical predictions about individual patients. For many infectious diseases, published prognostic scoring systems (PSSs) can help predict relevant outcomes. Validated PSSs exist for the general adult population for diseases such as pneumonia, endocarditis, meningitis, and bloodstream infection. Although these PSSs have been rigorously derived and validated, they have limited value in the care of older adults, because most studies have involved a heterogeneous adult population with mortality as the primary end point. In the United States, the number of patients who are > or =65 years old is growing, and their health care costs are increasing. Assessment of clinical outcomes other than merely survival (i.e., physical functional ability, cognitive ability, need for nursing home care, and overall quality of life) is required for this population. Some pioneering work has been done to develop PSSs that specifically address the health care needs of older adults. This review will describe existing PSSs and explore areas of further investigation.