Fifty women with recurrent symptoms of cystitis (urgent onset of painful and frequent voiding) were extensively examined bacteriologically. All were submitted to intravenous urography, cystoscopy, gynaecological and urodynamic examination and the urine was examined cytologically and by culture. A control group of 10 healthy women were submitted to the same bacteriologic examinations. Only in a few cases did the investigations give an explanation of the condition but, generally, the examination programme did not contribute to the etiology. Chlamydia trachomatis was found in 6%, which was comparable to the normal population. Gardnerella vaginalis must be considered as part of the normal flora. The extensive examination programme cannot be recommended as a routine.