BACKGROUND: Hostility has been shown to predict both the development and manifestation of coronary disease. Examining the inter-relation of dietary intake of fish and of polyunsaturated (n-3 and n-6) essential fatty acids with hostility may provide additional insights into the cardioprotective effect of dietary fish and polyunsaturated fatty acids. OBJECTIVE: To examine the association of dietary n-3, n-6 fatty acids and fish with level of hostility in a sample of 3581 urban white and black young adults. DESIGN: Cross-sectional observational study as part of an ongoing cohort study. A dietary assessment in 1992-1993 and measurement of hostility and other covariates in 1990-1991 were used in the analysis. RESULTS: The multivariate odds ratios of scoring in the upper quartile of hostility (adjusting for age, sex, race, field center, educational attainment, marital status, body mass index, smoking, alcohol consumption and physical activity) associated with one standard deviation increase in docosahexaenoic acid (DHA, 22:6) intake was 0.90 (95% CI=0.82-0.98; P=0.02). Consumption of any fish rich in n-3 fatty acids, compared to no consumption, was also independently associated with lower odds of high hostility (OR=0.82; 95% CI=0.69-0.97; P=0.02). CONCLUSIONS: These results suggest that high dietary intake of DHA and consumption of fish rich in n-3 fatty acids may be related to lower likelihood of high hostility in young adulthood. The association between dietary n-3 fatty acids and hostile personality merits further research.