Of 31 cases of haemorrhage from oesophageal varices treated by sclerotherapy eight came to necropsy. The oesophagus and proximal stomach were studied by means of a serial block technique and the histopathological findings in each case were recorded on two full-scale maps: one representing superficial tissues including the submucosa and the other the deeper tissues. The patterns of thrombosis, ulceration, necrosis, and fibrosis were studied in relation to the time interval since injection. Thrombosis and tissue necrosis were present within 24 hours of sclerotherapy, ulceration after seven days, and fibrosis after a month. Fibrosis was sometimes associated with stricture formation, which readily responded to dilatation. Patients with fibrosis had a reduced incidence of rebleeding.