OBJECTIVES: To assess cost-effectiveness of esomeprazole 40mg (SEK 14.68 / tablet: EUR 1 = SEK 9.27, June 15, 2005) once daily (od) versus omeprazole 20mg od at the lowest available generic drug price (SEK 4.32 / tablet) in the acute treatment of reflux esophagitis (RE) in Sweden. METHODS: A decision analysis model was used considering pooled effectiveness data from comparative clinical studies and patient management assumptions based on expert opinions. Results were analysed using an 8-week time horizon and reported separately including work productivity costs or direct medical costs (drugs, physician contacts, investigations) only. Utility values associated with having healed RE (0.84) or unhealed RE (0.69) were derived from a study using the rating scale method in patients with gastro-esophageal reflux disease (GERD). Estimates of GERD-related work productivity loss (absence from work and reduced productivity while at work) were derived from observed differences in productivity before and after treatment in another study. A probabilistic sensitivity analysis (PSA) on direct medical costs was used to assess robustness of results, along with additional analyses extending the time horizon beyond 8 weeks. An acceptable threshold of SEK 500,000 per quality-adjusted life year (QALY) gained was used in the PSA. RESULTS: When including direct medical costs only, the analysis resulted in mean additional costs of around SEK 200,000 per QALY gained by using the more effective acid inhibitory treatment strategy (esomeprazole). The PSA on the probability of esomeprazole treatment being below a SEK 500,000 per QALY gained threshold supported robustness of a conclusion that esomeprazole treatment is cost-effective. When work productivity costs were included, results indicated that the esomeprazole strategy is cost-neutral. Extending the time horizon resulted in further cost-effectiveness advantages for esomeprazole. CONCLUSION: Esomeprazole 40mg od is cost-effective compared with generic omeprazole 20mg od in the acute treatment of reflux esophagitis in Sweden.