Introduction - In 2006, a strain of Chlamydia trachomatis with a deletion in its cryptic plasmid was identified in Sweden. This strain is not detected by the molecular biology tests commonly used in France that target this plasmid sequence. Methods - As part of their surveillance mission, the National Reference Center for Chlamydia Infections (CNR) and the French Institute for Public Health Surveillance (InVS) conducted a study involving laboratories. This strain was screened for in 3,082 urogenital samples from various geographic locations, of which 1,645 were positive for C. trachomatis. Results - The new variant was detected in one case, that of a non-French woman from the European Union who visited an anonymous screening center in Bordeaux. Conclusion - The new variant does not appear to have established itself in France at this time, but surveillance based on the analysis of samples that tested positive using a method that detects the variant must continue. (R.A.)