In order to investigate the role of the hemostatic, fibrinolytic and inflammatory system in unstable angina, we assessed the levels of thrombin-antithrombin III (TAT), Prothrombin Fragment 1+2 (F1+2), plasmin-antiplasmin (PAP) and D-Dimer (DD) and of C-reactive protein (CRP) in 51 patients admitted to our CCU with severe unstable angina. Thirty-one pts had a complicated in hospital course (G1), levels of CRP and PAP were significantly higher in this group than in patients with non complicated in-hospital course (G2). Using the probit transformation we assessed the following cut-off point between G1 and G2: 2.5 μg/1 for TAT, 0.9 nmol/ml for F1+2, 13 μg/l for DD, 500 μg/l for PAP, and 3.5 mg/l for CRP. Our study provides further evidence of the importance of markers of inflammation and fibrinolysis in unstable angina, and demonstrates the utility of data analysis by probit transformation. © Pearson Professional Ltd 1996.