BACKGROUND AND AIM: There is considerable controversy as to whether fasting can be recommended to patients with cardiovascular disease. The objective of this study was to determine whether a well-known method of 1-week subtotal fasting affects hemostasis in healthy subjects. METHODS AND RESULTS: Analyses were carried out before, four times during and 3 days after fasting in 12 fasting subjects (< 300 kcal/day, only from carbohydrates) (group 1), and 8 control subjects (group 2). Plasmatic coagulation (prothrombin time, partial thromboplastin time, p < or = 0.001) and fibrinolysis (plasminogen, plasmin-antiplasmin-complex, p < 0.05) increased during fasting but remained within the normal limits. While the platelet count was similar in both groups, platelet sensitivity to stimulators was reduced in group 1 (P-selectin and activated GP IIb/IIIa on ADP-stimulated platelets, p < or = 0.01). Furthermore, soluble P-selectin (p < or = 0.01) and C-reactive protein were decreased in comparison to group 2 (p < or = 0.05). CONCLUSIONS: Hemostasis and inflammation parameters during 1-week subtotal fasting do not imply an increase in cardiovascular risk.