Background: The incidence of ischemic heart disease (IHD) in Crete was lower than expected on the basis of blood lipid concentrations of participants in the Seven Countries Study. A favorable effect of a high intake of olive oil on thrombogenesis may have contributed to this finding. Objective: We compared the effects of virgin olive oil with those of rapeseed and sunflower oils on blood coagulation factor VII (FVII), a key factor in thrombogenesis. Design: In a randomized and strictly controlled crossover study, 18 healthy young men consumed diets enriched with 5 g/MJ (19% of total energy) olive oil, sunflower oil, or rapeseed oil for periods of 3 wk. On the final day of each period, participants consumed standardized high-fat meals (42% of energy as fat). Fasting and nonfasting blood samples were collected after each period. Results: Mean (±SEM) nonfasting peak concentrations of activated FVII (FVIIa) were 11.3 ± 5.1 U/L lower after olive oil than after sunflower oil, all 18% reduction (P < 0.05). Olive oil also tended to cause lower FVIIa peak concentrations than did rapeseed oil (mean difference: 8.6 U/L, a 15% reduction; P = 0.09). There were no significant differences between diets with respect to nonfasting factor VII coagulant activity (FVII:c), prothrombin fragment 1+2 (F1+2), and tissue factor pathway inhibitor (TFPI) concentrations, or with respect to fasting plasma values of FVII protein, FVII:c, FVIIa, F1+2, or TFPI. Conclusion: A background diet rich in olive oil may attenuate the acute procoagulant effects of fatty meals, which might contribute to the low incidence of IHD in Mediterranean areas.