BACKGROUND Although previous studies have indicated that performance assessments strongly predict future survival, few have evaluated the incremental value in the presence of controls for self-reported activity and mobility limitations. OBJECTIVE We assess and compare the added value of four tests  walking speed, chair stands, grip strength, and peak expiratory flow (PEF)  for predicting all-cause mortality. METHODS Using population-based samples of older adults in Costa Rica (n = 2290, aged 60+) and Taiwan (n = 1219, aged 53+), we estimate proportional hazards models of mortality for an approximate five-year period. Receiver Operator Characteristic (ROC) curves are used to assess the prognostic value of each performance assessment.