Vonoprazan is a potent inhibitor of gastric acid secretion and may have better response than proton pump inhibitors (PPIs) in the treatment of endoscopic submucosal dissection induced artificial ulcers. However, reported outcomes remain controversial. In this study, we conducted a prospective, randomized comparative trial to evaluate healing effects of vonoprazan and lansoprazole on endoscopic submucosal dissection (ESD)-induced ulcers. We enrolled 216 patients who underwent endoscopic submucosal dissection for early gastric neoplasms. They were randomly divided into vonoprazan (20 mg/day) and lansoprazole (30 mg/day) groups. The primary endpoint was the reduction rate of ulcer and complete healing (scar) ratio of ESD-induced ulcers at 4 and 8 weeks. Finally, 101 patients of the vonoprazan group and 95 patients of the lansoprazole group were included in the analysis. There were no significant differences in the reduction rate between the vonoprazan and lansoprazole groups at either timepoint (4 weeks, 94.0 vs 93.4%; 8 weeks, 99.8 vs 99.9%, respectively). The complete healing ratio at 4 and 8 weeks did not differ significantly between the vonoprazan and lansoprazole groups (4 weeks, 11.9 vs 12.6%; 8 weeks, 87.1 vs 86.3%, respectively). In the anti--antibody negative or positive patients, there were no significant differences in the reduction rate and complete healing ratio between the vonoprazan and lansoprazole groups. Regardless of treatment choice, the overall complete healing ratio at 8 weeks was significantly higher in the anti--antibody negative patients than the positive patients ( = 0.006). The healing effects of vonoprazan on ESD-induced ulcers were comparative to those of lansoprazole.