Objective: White matter (WM) microstructural changes areincreasingly recognized as a mechanism of age-related cognitive differences.This study examined the associations between patterns of WM microstructure andcognitive performance on the University of California, San Francisco (UCSF)Brain Health Assessment (BHA) subtests of memory (Favorites), executivefunctions and speed (Match), and visuospatial skills (Line Orientation) within asample of older adults. Method: Fractional anisotropy (FA) in WMtracts and BHA performance were examined in 84 older adults diagnosed asneurologically healthy (47), with mild cognitive impairment (19), or withdementia (18). The relationships between FA and subtest performances wereevaluated using regression analyses. We then explored whether regional WMpredicted performance after accounting for variance explained by global FA.Results: Memory performance was associated with FA of thefornix and the superior cerebellar peduncle; and executive functions and speed,with the body of the corpus callosum. The fornix–memory association andthe corpus callosum–executive association remained significant afteraccounting for global FA. Neither tract-based nor global FA was associated withvisuospatial performance. Conclusions: Memory and executivefunctions are associated with different patterns of WM diffusivity. Findings addinsight into WM alterations underlying age- and disease-related cognitivedecline.