Reiter's disease patients (RD, 83 per cent) were divided into five groups according to the causative agent. The clinical variants were compared. For the clinical picture of Chlamydia-associated RD follicular lesions of the cervical, rectal, and conjunctival mucosa are characteristic; latent forms prevail with initial joint syndrome and enteropathy. RD of Chlamydia-ureaplasma aetiology is characterised by extensive clinical manifestation with obligatory involvement of the sacro-iliac joint. Enterocolitis RD is epidemic, highly active, with pronounced fever syndrome and a more favourable prognosis.