The basis for the diagnostic work-up of recurrent cystitis is formed by taking a precise medical history against the background of knowledge of the pathogenesis of urinary tract infections. The anamnesis should also focus on factors that influence the natural flora (sexual intercourse, hygiene) but additionally include preceding antibiotic treatment and diseases that affect the immune status (diabetes mellitus). Urinalysis is the principal examination among the laboratory diagnostic procedures. The diagnosis is promptly confirmed by immediate analysis of a clean catch midstream urine sample using a counting chamber or a test strip. As a matter of principle, microbiological diagnosis always ensues. Extended diagnostic work-up (urological staging) is aimed at detecting functional and anatomic abnormalities. While these factors only play a subordinate role during the premenopausal phase, they gain in importance during the postmenopausal phase. A key role is also attributed to local estrogen deficiency.