Interstitial cystitis (IC) is still considered a rare disease, but in the future its incidence will probably be revised if tendency is that of considering interstitial cystitis on the basis of clinical rather than endoscopic-histological criteria. According to some urologists, cystodistension and vesical biopsy, even if not pathognomonic, are still effective up till now, at least for their prognostic-therapeutic value as well. If on one hand in the diagnosis of this condition symptoms tend to be of more and more value unlike instrumental investigations, on the other hand little has changed in therapy.