In order to establish whether injection sclerotherapy of oesophageal varices could bring about a worsening of the coagulation abnormalities of patients with cirrhosis, the platelet count and the coagulation profile were monitored prior to, then 30 min and 18 h after, the injection in 8 patients undergoing 18 sclerotherapy sessions. Under basal conditions the platelet count, prothrombin activity, normotest and antithrombin III were all reduced; fibrinogen was in the low, and partial thromboplastin time in the high, normal range. A significant shortening of PTT and a further reduction in the platelet count, in the normotest and in fibrinogen occurred after 30 min. On one occasion laboratory evidence of disseminated intravascular coagulation was observed. After 18 h most parameters approached basal values, but the normotest remained persistently reduced. Even though a transient activation of the coagulation process, with consumption of platelets and the liver-dependent clotting factors took place after sclerotherapy in most cases, leading in one to self-limiting disseminated intravascular coagulation, haemorrhagic complications did not occur in our patients. These results suggest that injection sclerotherapy did not lead to clinically significant deterioration of coagulation even in patients with abnormal coagulative function. The observed changes appeared to be self-limiting and confined to the laboratory level in all cases.