Coagulation studies in the syndrome of haemolysis, elevated liver enzymes and low platelets. The presence of disseminated intravascular coagulation (DIC) in the syndrome of haemolysis, elevated liver enzymes and low platelets (HELLP) is debated. We assessed the occurrence of decompensated and compensated DIC (using predefined criteria) in 15 consecutive nulliparous pregnant patients with gestational hypertension combined with the HELLP syndrome and in 12 consecutive nulliparous controls with pregnancy induced hypertension (PIH) but without the HELLP syndrome. A combination of routine coagulation assays revealed the absence of decompensated DIC in all studied patients. However, using more specific and sensitive coagulation assays, compensated DIC was observed in all HELLP patients and in three patients in the control group. The mean values of antithrombin III, thrombin-antithrombin III complexes and protein C in the HELLP and the control group were 66 vs 87% (P = 0.0004), 21 vs 8 ng/ml (P = 0.0008) and 57 vs 90% (P = 0.0018) respectively. We conclude that HELLP patients show evidence of compensated DIC which may have pathophysiological significance for the observed organ damage. 