Background: The Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets are characterized by higher intake of fruit, vegetables, whole grains, and unsaturated fatty acids. All of these foods and nutrients may affect cholesterol, inflammation, the development of atherosclerosis, and, therefore, risk of cardiac death. Objective: Our objective was to examine the association between the Mediterranean and DASH dietary patterns and risk of sudden cardiac death (SCD) in women. Design: We used a prospective cohort of 93,122 postmenopausal women enrolled in the Women's Health Initiative study between 1993 and 1998 and followed for an average of 10.5 y. Women completed a food-frequency questionnaire (FFQ) twice during follow-up. We scored their diets according to how closely the reported diet resembled each dietary pattern. SCD was defined as death that occurred within 1 h of symptom onset. Results: A higher Mediterranean diet score was associated with lower risk of SCD (HR: 0.64; 95% CI: 0.43, 0.94) when women in the highest quintile were compared with women in the lowest quintile after adjustment for age, total energy, race, income, smoking, and physical activity. After adjustment for potential mediators, the association was similar (HR: 0.67; 95% CI: 0.46, 0.99). A higher DASH diet score was not associated with risk of SCD. However, sodium intake, which is a crucial component of the DASH dietary pattern, was not well characterized by the FFQ. Conclusion: The Mediterranean dietary pattern may be associated with lower risk of SCD in women. This trial was registered at clinicaltrials.gov as NCT00000611. © 2014 American Society for Nutrition.