We report the results of a systematic direct detection screening protocol for Chlamydia trachomatis in urine samples from young women.The study included 1026 patients aged 13 to 30 years. Urine samples were tested with a molecular biology assay: AMP-CT.Thirty-five patients (3.4%) were positive: 80% of the positive patients were aged less than 25 years, 48.6% less than 20 years. All these patients were treated and post treatment controls were negative.This study suggests that national screening programs for Chlamydia trachomatis could be beneficial for women aged between 15 and 25 years and that the "Calmat" law could be modified in consequence.