Forty-five consecutive patients underwent sclerotherapy with absolute alcohol. Post-sclerotherapy ulcers were detected in all of them (100%) on the following day. In order to evaluate its influence on ulcer healing, 20 patients were given sucralfate (1 g QID before meals), while 25 patients received identical-looking placebo, in a double-blind randomised manner. Endoscopy done at weekly intervals revealed healing of ulcers in 25%, 55%, 95% and 100% in the sucralfate, and 24%, 40%, 72% and 84% in the placebo group at 1, 2, 3, and 4 weeks, respectively. Differences between the two groups were not significant. Gastric variceal ulcers healed better with sucralfate (7 out of 7) than placebo (0 out of 2). Healing was influenced by the size of the ulcer. At two weeks, 63% of ulcers less than 1 cm, 43% of ulcers 1-2 cm, and only 16.6% of ulcers greater than 2 cm had healed. The size of the ulcer also correlated with the amount of the sclerosant injected. Our results show that (a) mucosal ulcers universally develop after adequate sclerotherapy, (b) most ulcers heal spontaneously, (c) sucralfate does not hasten ulcer healing, with the exception of gastric variceal ulcers, (d) a larger amount of sclerosant produces larger ulcers that take longer to heal.