OBJECTIVES: To evaluate two screening programs for Chlamydia Trachomatis (CT) in France by measuring cost per case and cost per treated case.METHODS: We evaluated the cost-effectiveness ratios of two CT screening strategies using a decision tree model. Strategy A involved screening of asymptomatic women only with partner notification; Strategy B involved screening of both asymptomatic men and women with partner notification. The current strategy of no screening was not evaluated. Clinical pathways were validated by a panel of experts. Direct cost analysis was performed from the point of view of the French National Health Insurance System. RESULTS: Overall, 347 women, and their partners could be treated by strategy A, and 296 individuals and their partners by strategy B. The total cost of strategy B was lower than that of strategy A (€213,400 compared to €250,558). Costs per case and costs per treated case were comparable for the two strategies, €557 and €722 respectively. According to a sensitivity analysis, the key variables were: CT prevalence, male participation rate, and likelihood that a man should consult a doctor.CONCLUSIONS: This is the first model for CT screening built on French data and thus a useful tool for French health policy decision-makers as it provides estimates for budgetary impact analysis. Its limitations are the hypotheses on which it is based (averted outcomes, direct costs...). Besides comparing the cost-effectiveness of screening, our study highlighted the need to standardize clinical practice and develop a good communication program.