It is generally believed that a chlamydial eye infection in adults is the result of autoinoculation of the eye by infected genital secretion. Genital samples of 60 microbiologically verified, adult, non-trachomatous chlamydial conjunctivitis cases were investigated. Only two of the 38 men and none of the 22 women tested had symptoms of genital infection when the sampling was made for establishing the diagnosis of chlamydial infection. Of the men, 23 (61%), 20 (53%), 19 (50%), and 20 (53%) were positive in urethral samples by culture, ELISA (Chlamydiazyme, Abbott, USA), and immunofluorescence tests (Chlamyset, Orion, Finland and MicroTrak, Syva, Finland), respectively. The corresponding figures for the female urethral samples were 12 (55%), 11 (50%), 9 (41%), and 12 (55%) and for the cervical samples 15 (68%), 15 (68%), 14 (64%), and 14 (64%), respectively. Thirty-nine mothers to neonates with chlamydial conjunctivitis were also studied. In 34 (87%) of the mothers, a genital chlamydial infection could be verified. It has been a general belief that the eye in chlamydial conjunctivitis in adults is generally infected by autoinoculation of infected genital secretion. Different means to explain the discrepancy between the results of the diagnostic tests for the eye and genital samples are considered.