Standardized diagnostic procedures including microbiologic and cytologic examinations of expressed prostatic secretions (EPS) are prerequisites for a correct classification of prostatitis syndromes and a rational therapeutic approach. In fact, only a small proportion of patients suffer from bacterial prostatitis and may thus benefit from modern antimicrobial therapy with fluoroquinolones. For the majority of patients, the 'non-bacterial' inflammatory condition is of unknown etiology: effective therapy of this type of prostatic inflammation is yet to be found. Further basic clinical, microbiologic and immunologic studies are urgently needed to elucidate this complex entity often frustrating both patient and urologist.