Abstract Objective: The current study aims to describe the Mediterranean diet (MD) adherence across the US regions, and explore the predictive factors of MD adherence among US adults. Design: Cross-sectional secondary data analysis. MD adherence score (0-9) was calculated using the Block 98 FFQ. Hot spot analysis was conducted to describe the geospatial distribution of MD adherence across the US regions. Logistic regression explored predictors of MD adherence. Setting: Nationwide community-dwelling residency in the USA. Participants: Adults aged ≥45 years (n 20 897) who participated in the REasons for Geographic and Racial Differences in Stroke study and completed baseline assessment during January 2003 and October 2007. Results: The mean of MD adherence score was 4·36 (sd 1·70), and 46·5 % of the sample had high MD adherence (score 5-9). Higher MD adherence clusters were primarily located in the western and northeastern coastal areas of the USA, whereas lower MD adherence clusters were majorly observed in south and east-north-central regions. Being older, black, not a current smoker, having a college degree or above, an annual household income ≥ $US 75K, exercising ≥4 times/week and watching TV/video <4 h/d were each associated with higher odds of high MD adherence. Conclusions: There were significant geospatial and population disparities in MD adherence across the US regions. Future studies are needed to explore the causes of MD adherence disparities and develop effective interventions for MD promotion in the USA.