PURPOSE: The effectiveness of using anti-adhesion agents in laparoscopic surgery is controversial. We compared the outcomes of patients exposed to anti-adhesion agents (barrier group) with those of patients not exposed (no barrier group) in laparoscopic surgery. METHODS: Using a nationwide claim-based database in Japan, we analyzed data from patients who underwent laparoscopic surgery between 2005 and 2019 and compared the patient characteristics and the proportion of those with bowel obstruction between the barrier and no barrier groups. We also performed several sensitivity and subgroup analyses. RESULTS: Of the 57,499 patients who met the inclusion criteria, 14,360 and 43,139 were assigned to the barrier and no barrier groups, respectively. The proportion of patients with a bowel obstruction in the two groups did not differ among all patients hospitalized for obstruction (1.1 vs. 1.1%, p = 0.63) and those requiring surgery (0.2 vs. 0.2%, p = 0.39). In the sensitivity analysis with propensity score matching, the incidences of bowel obstruction between the barrier and non-barrier groups were equivocal (1.3 vs. 1.6%), but statistically marginal (chi-square test, p = 0.035; log-rank test, p = 0.09). CONCLUSION: The use of barrier agents for adhesive prevention did not show clear effectiveness for the prevention of bowel obstruction after laparoscopic surgery for unselected cases. Further studies focusing on more specific procedures are needed.