The eight FICSIT (Frailty and Injuries: Cooperative Studies of Intervention Techniques) sites test different intervention strategies in selected target groups of older adults. To compare the relative potential of these interventions to reduce frailty and fall-related injuries, all sites share certain descriptive (risk-adjustment) measures and outcome measures. This article describes the shared measures, which are referred to as the FICSIT Common Data Base (CDB). The description is divided into four sections according to the four FICSIT committees responsible for the CDB: (1) psychosocial health and demographic measures; (2) physical health measures; (3) fall-related measures; and (4) cost and cost-effectiveness measures. Because the structure of the FICSIT trial is unusual, the CDB should expedite secondary analyses of various research questions dealing with frailty and falls.