Background and Aims. Older adults with chronic vascular comorbidities may report with subjective cognitive decline (SCD) or decline in cognitive performance over time and concomittant e everyday functional difficulties, perhaps associated with psychological distress. Yet, the role of functional difficulties and psychological distress in the relationship between chronic vascular comorbidities and SCD remains unknown. This study aimed to examine the association between chronic vascular comorbidities and subjective cognitive decline (SCD) by functional difficulty and psychological distress mediation in middle to older adults with cancer survivors. Methods. Data were from 1293 adult cancer survivors aged 45 to ≥80 (72.2 % females) from the the 2019 wave of the U.S. Centers for Disease Control Behavioral Risk Factor Surveillance System . Incluson criteria were middle to older adults with chronic vascular comorbidities who self-reported their SCD and functional difficulties and psychological distress. Results. Chain mediation analysis showed higher SCD with higher chronic vascular comorbidities. Psychological distress and functional difficulties serially mediated the relationship (indirect effect = .042, 95% CI .025 to .062), with a 9.01% overall mediation effect. Psychological distress alone did not mediate the relationship between chronic vascular comorbidities and SCD, but functional difficulties were the most signficant, with a 43.3% mediation effect. Conclusion and implication. Functional difficulties explain a larger portion of the effects of chronic vascular comorbidities on the odds of SCD in adult cancer survivors than psychological distress. Future research could examine if these findings are unique to the adult cancer survivor population or perhaps other health populations self-reporting cognitive changes.