To evaluate the cost utility and the budget impact of adjuvant racecadotril for the treatment of acute diarrhea in children in Thailand.A cost utility model has been adapted to the context of Thailand to evaluate racecadotril plus oral rehydration solution (R+ORS) versus oral rehydration solution (ORS) alone for acute diarrhea in children <5 years old. The decision tree Excel model evaluates the costs and effects (quality-adjusted life years) over a 6-day time horizon from a public health care payer's perspective in Thailand. Deterministic sensitivity analysis and budget impact analysis have been undertaken.According to the cost utility model, the intervention (R+ORS) is less costly and more effective than the comparator (ORS) for the base case with a dominant incremental cost-effectiveness ratio of -2,481,390฿ for the intervention. According to the budget impact analysis (assuming an increase of 5% market share for R+ORS over 5 years), the year-on-year reduction for diarrhea as a percentage of the total health care expenditure is -0.0027%, resulting in potential net cost savings of -35,632,482฿ over 5 years.Subject to the assumptions and limitations of the models, adjuvant racecadotril versus ORS alone is potentially cost-effective for children in Thailand and uptake could translate into savings for the Thailand public health care system.