INTRODUCTION:
High educational attainment and regular physical activity (PA) are fundamental for cognitive health. We aimed to investigate whether the association between PA levels and mild cognitive impairment (MCI) varies according to education level in Brazilians (≥50 years).

METHODS:
Cross-sectional study of the second wave (2019-2021) of the Longitudinal Study of the Health of Brazilian Elderly (ELSI-Brasil). Education level was categorized as low (illiterate), medium (completed primary education), and high (secondary education or higher). PA was classified as physically inactive (<10 min/week moderate activity or walking and <10 min/week vigorous activity) and sufficiently active (≥150 min/week of moderate activities or ≥75 min/week of vigorous activity). MCI was defined with a global cognition z-score ≤-1.5 and preserved instrumental activities of daily living. Associations were assessed using Pearson's chi-square test and Poisson regression with robust variance, estimating Prevalence Ratios (PR) and 95% confidence intervals (CI).

RESULTS:
In the sample of 7,308 participants, the prevalence of MCI was 5.25%. Inactive individuals with low education levels were associated with MCI (PR=11.27; 95% CI: 6.10–20.81)**, as were those inactive with average education levels (PR=4.26; 95% CI: 2.37–7.83)**. Sufficiently active individuals with low education levels (PR=8.42; 95% CI: 4.40–16.12)** and sufficiently active with average education levels (PR=2.24; 95% CI: 1.20–4.20)* were also associated with MCI. (**p<0.001; *p<0.05)

CONCLUSIONS:
The association between PA and MCI varies according to the level of education. Even in the sufficiently active group, both in combination with low and average education levels, they remained associated with a higher prevalence of MCI. These results reinforce the importance of strategies to expand schooling and promote PA for the prevention of MCI.