Between January 1994 and January 2000 we analyzed a series of 440 cases with urethral structures (US) in which we performed internal urethrotomy (IU). Bulbous site (76%), inflammatory etiology (84%) and primary disease (74%) were the characteristics of our series of patients. The diagnosis protocol was based on classical evaluation, urethral echography (7-10 MHz and endorectal Multiplan) and, in 37 cases, histopathological analysis of urethral callus. Based upon echographic description of the structural zone, the endo-incision was performed only at 12 o'clock position in 205 cases (46.8%), at 6 and 12 o'clock positions in 71 cases (16%), "star incision" in 141 cases (32%) and only at 6 o'clock position in 23 cases (5.2%). The recurrence rate was 15.7% (69 cases) after a follow-up period of 2 to 36 months. In 37 cases with urethral biopsy from structural zone, we described a high recurrence rate (62.5%) with "local active inflammation". Complementary treatment with anti-inflammatory drugs reduced this rate to 10% of cases. Our significative study revealed that echographic and histopathological evaluation of US could increase the efficiency of endourological treatment in this pathology; urethral ultrasound could be the first choice in the diagnostic of US and could establish the "perfect" site of endo-incision.