Background <p>Mindfulness awareness is significantly associated with cognitive reappraisal, a key emotion regulation strategy. Guided by the Mindful Coping Model and Socioemotional Selectivity Theory, this cross-sectional study investigated the link between mindfulness awareness and cognitive reappraisal in individuals with mild cognitive impairment (MCI), exploring the potential mediating role of cognitive flexibility and the moderating role of age.</p> Methods <p>Participants with MCI (<i>N</i> = 219) were recruited from five tertiary hospitals and two community healthcare centers in Jiangsu Province, China. Data on mindfulness awareness, cognitive flexibility, cognitive reappraisal, and covariates were collected.</p> Results <p>A significant positive association was found between mindfulness awareness and cognitive reappraisal (β = 0.324, 95% CI [0.205, 0.442]). Cognitive flexibility showed a significant mediating role in this relationship (β = 0.068, 95% CI [0.011, 0.154]). Age significantly moderated both the direct (β = 0.389, <i>P</i> = 0.002) and indirect (β = -0.532, <i>P</i> &lt; 0.001) pathways between mindfulness awareness and cognitive reappraisal. Simple slope analyses showed a significant direct effect in older participants (β = 0.461, <i>P</i> &lt; 0.001), but not in middle-aged participants; conversely, the indirect effect via cognitive flexibility was significant in middle-aged participants (β = 0.666, <i>P</i> &lt; 0.001) and marginally significant in older participants (β = 0.134, <i>P</i> = 0.050).</p> Conclusions <p>Findings suggest mindfulness awareness and related cognitive flexibility are associated with cognitive reappraisal in MCI, with age influencing this relationship. Future interventions targeting these components and tailoring approaches by age group may support emotion regulation in this population.</p>