Objectives This article reports the fortuitous recovery of nine Chlamydia trachomatis serovar L strains in cell cultures (Vero and LLC-MK₂ cell line) designed for viral culture.

Methods Nine ano-genital swabs were inoculated on confluent Vero, MRC5 and LLC-MK₂ cell cultures. They were collected from HIV-positive patients who were primarily men who have sex with men (MSM) presenting ulcerations that mimicked herpes simplex infections.

Results A cytopathogenic effect was observed on Vero and LLC-MK₂ cells on day 14. The presence of C trachomatis serovar L in the cell lines was confirmed by Real Time–PCR.

Conclusions C trachomatis serovar L can grow on Vero and LLC-MK₂ cell lines designed for viral cultures. Lymphogranuloma venereum must be considered as a differential diagnosis for herpes-like lesions, particularly in MSM with high-risk behaviours.