[eng] Studies examining the interplay between chronic pain, cognitive function, and functional brain abnormalities in older adults are scarce. To address this gap, we administered a series of neuropsychological tests and recorded electroencephalography (EEG) data during resting-state conditions in 26 older adults with chronic pain (CPOA), 30 pain-free older adults (OA), and 31 younger adults (YA). CPOA demonstrated poorer performance compared to OA on the Stroop test, the Wisconsin Card Sorting Test (WCST) and Digit Span. Both groups of older adults exhibited higher beta activity compared to younger adults, with CPOA displaying particularly elevated beta-2 activity localized in the posterior cingulate cortex compared to OA. Correlational analyses indicated that in CPOA participants, heightened beta activity was linked to decreased performance on the WCST. Conversely, in OA, we observed a positive correlation between beta activity and performance on the WCST. Overall, our f indings suggest that the cumulative impact of pain in aging would diminish the effectiveness of the functional compensatory mechanisms that occur during healthy aging, exacerbating cognitive decline.