OBJECTIVE: Upper respiratory tract infections are frequent in children. Their economic impact is widely unknown. This study responded to a request from the French Economic Committee to estimate the direct cost of an acute rhino-pharyngitis (ARP), the effectiveness of Imocur® (OM-85 BV indicated for the prevention of recurrences), and the cost effectiveness of this strategy compared to placebo from a Social Security perspective. METHOD: Costs, probabilities of short-term complications, associated care, effectiveness of Imocur® during the winter period were based on review of the literature, national health statistics and consulting experts’ opinions. An incremental cost-effectiveness model was used. RESULTS: The mean direct cost for an ARP is 49.5 €. Among children with recurrent infection, 1.52 infections during the winter period is avoided using this type of prevention and Social Security saves approximately 68 € per child on the cost of care. The sensitivity analyses confirm the robustness of the model. They show that prevention with Imocur® allowed Social Security to save between 28 and 304 € in direct costs for each at-risk individual who received preventive treatment. The threshold analysis shows that this type of prophylaxis is economically profitable for the community starting from 0,15 prevented infections and direct costs of care of an acute infection exceeding 4.77 €. The demonstration is valid with recurrently-infected children, a population for which the effectiveness of Imocur® has been established. If we had taken into account other payers’ view points and the indirect costs, our conclusions would have been reinforced. CONCLUSION: Non-specific immunotherapy is a reasonable measure to be considered for prevention of recurrences and should be associated with recommended measures in children at risk. The French health authorities in assessing its usefulness considered the economic value to the community of an effective medication.