The efficacy of transrectal microwave hyperthermia (TMH) was investigated in 124 patients aged 20 to 55 years. Of them, 75 (60.5%) patients had chronic noninfectious and 49 (39.5%) patients infectious prostatitis. In addition to standard pre- and posttreatment examinations the following tests were made: bacteriological and biochemical tests of prostatic secretion, uroflowmetry, transrectal color Dopplerographic mapping. The course of the treatment included 10 one-hour sessions of microwave hyperthermia, drug therapy and prostatic massage. Patients with both forms of chronic prostatitis exhibited disorders of prostatic circulation, activated lipid peroxidation, low concentration of catalase in the organ secretion, defective urodynamics of the lower urinary tracts. More pronounced changes occurred in noninfectious process. Microwave hyperthermia produced clinical improvement, recovery of hemodynamics in the prostate, structure and function of cell membranes in prostatic secretion, positive response of urodynamics. Thus, TMH generated on domestic equipment can be considered as one of the methods of pathogenetically sound treatment of noninfectious and infectious chronic prostatitis.