The trial entered 49 patients with epididymitis and 18 age-matched control subjects without this disease. The patients were divided into 3 groups: 21 patients of group 1 were treated surgically (epididymotomy with drainage of the scrotal cavity), 15 patients of group 2 were inoperable, 13 patients of group 3 suffered from exacerbation of chronic epididymitis. Before treatment the patients were examined clinically, bacteriologically and immunologically. Measured were: main populations and subpopulations of lymphocytes using indirect immunofluorescence and monoclonal antibodies; concentration of serum immunoglobulins using radial immunodiffusion; overall content of circulating immune complexes precipitating by polyetilene glycol-6000; phagocytosing neutrophil function by absorption of latex particles. The immunogram of epididymitis patients was indicative of the inflammation stage and activity which is important for choice of treatment. Immunogram of group 1 patients was characteristic of the peak of acute inflammation, of group 2 was typical for attenuation of acute inflammation. Immunogram of group 3 patients corresponded to exacerbation of chronic inflammation and secondary immunodeficiency.