Frailty and cognitive impairment often coexist in older adults, but whether frailty affects specific cognitive domains remains unclear. In this study, we examined the relationship between frailty and domain-specific cognitive performance in 2,414 older adults from a Thai aging cohort without dementia. Participants were classified as cognitively unimpaired (CU) or mild cognitive impairment (MCI), and cognitive function was assessed using the Montreal Cognitive Assessment (MoCA).

Among participants with MCI, frailty was associated with poorer global cognition and significantly lower performance in visuospatial/executive function, naming, and language. In contrast, frailty was not associated with differences in global or domain-specific cognition among cognitively unimpaired participants.

These findings suggest that frailty does not uniformly reduce cognitive performance but instead modifies the expression of cognitive impairment once cognitive decline is present. Incorporating frailty assessment alongside domain-level cognitive evaluation may improve risk stratification and support more targeted interventions for older adults at risk of further cognitive decline.