The ability of sucralfate to prevent gastric mucosal erosions caused by long-term aspirin ingestion was studied in 19 normal human subjects. A placebo-controlled, double-blind, crossover design was used to study the capacity of 4 g sucralfate daily to lessen the noxious effect on gastric mucosa of 3.6 g aspirin daily for 14 days. Gastric mucosal injury was assessed by endoscopic scoring of erosions. There was no significant difference in mean erosion scores or the degree of partial mucosal protection between the two groups. It was concluded that sucralfate lacks a mucosal protection capacity at the dosage studied in human subjects ingesting large doses of aspirin over a two-week period.