A total of 168 patients with various ocular diseases were tested for Chlamydia. Scrapings off the conjunctiva were examined by the fluorescent antibody technique with monoclonal antibodies. A high diagnostic efficacy of the method in patients with acute and, which is even more important, with the subacute form of ophthalmic chlamydiasis was demonstrated. Moreover, the method effectively diagnosed ophthalmic chlamydiasis in patients with inflammations of the anterior and median segments of the eye of obscure etiology.