BACKGROUND/AIMS: Long-term use of aspirin can be a risk factor of peptic ulcer diseases. The aim of this study was to evaluate the efficacy of Albis (Daewoong Pharmaceutical Co., Ltd.) for the prevention of gastric mucosal injury caused by aspirin. METHODS: Aspirin users were enrolled and randomized into the Albis or placebo group. Screening and follow-up endoscopy were performed for modified Lanza scores (MLSs). Primary outcome was measured by the incidence rate of peptic ulcer, and secondary outcomes were measured by the incidence rate of gastritis, improvement in MLS and subjective symptoms. RESULTS: In total, 81 aspirin users were randomized, 43 in the Albis group and 38 in the placebo group. There was no incidence of peptic ulcer in both groups. The incidence of gastritis was significantly higher in the placebo group (44.4% vs. 10.0%, p=0.003); however, the scores of mucosal edema, hyperemia and hemorrhage were not statistically different between the two groups (p>0.05). The frequency of subjective symptoms were more improved in the Albis group than in the placebo group (p=0.023). CONCLUSIONS: The incidence of gastritis was lower in the group that received low-dose aspirin and Albis. The development of peptic ulcer due to long-term use of aspirin might be prevented with concomitant use of Albis.