Identification of conjunctival chlamydioses could be very difficult since this disease is extremely latent. Moreover previous instillation of topical antibiotic provokes a negativation of D.I.F. and of cultures. P.C.R. is very useful, it was demonstrative in 41 cases out of 47 cases; D.I.F. was positive only in 18 cases. P.C.R. is a very promising method to recognize chlamydiae; identification of different serovars is processing.