It has been suggested that the fatty acid composition of serum phospholipids is an independent risk factor for cardiovascular disease. We examined the association of the fatty acid composition of serum phospholipids with fibrinogen, factor VII antigen (FVII:Ag), factor VII coagulant activity (FVII:C), plasminogen, and lipoprotein(a) [Lp(a)] in 338 men and 363 women 45 to 64 years old. Palmitic acid, the most abundant saturated fatty acid, was positively associated in univariate analyses with plasminogen, which explained 5.2% of its variance among men (P<.0001) and 5.8% among women (P<.0001). Linoleic acid, which is the most abundant polyunsaturated fatty acid, was negatively associated with plasminogen and fibrinogen. This explained 1.1% of the variance in fibrinogen among men (P=.04) and 3.2% among women (P=.0006) and 4.1% of the variance in plasminogen in both sexes (P<.0001). Dihomogammalinolenic acid was positively associated with FVII:Ag and explained 3.7% of its variance among men (P=.0003) and 4.6% among women (P<.0001). Furthermore, dihomogammalinolenic acid was positively and significantly associated with FVII:C, fibrinogen, and plasminogen among women but not among men. All these associations remained significant after adjustment for multiple potential confounding factors such as age, smoking, serum lipids, and body mass index. In conclusion, our findings suggest that linoleic acid, palmitic acid, and dihomogammalinoleic acid are significant independent determinants of hemostatic profile. It is not clear, however, to what extent these results reflect the effects of fatty acids on coagulation and to what extent they reflect the activity of inflammatory processes in the arteries.