The application of a small-sized lithotriptor for the extracorporeal shock-wave treatment (ESWT) of La Peyronie's disease (PD) was originally suggested by Butz, in 1996. In November 1996 we started to use this method with the aim of checking its tolerability and effectiveness. From April 1998, we standardized our protocol treatment as follow: higher treatment frequency: each every other day; higher energy density value: at least level "4" (= 0.11 mJ/sqmm). From March 1998 to May 2000, 82 patients with PD, aged between 44 and 74 (average age 53.8) were treated according to this protocol. A case history was drafted for each patient and they all underwent an objective examination, a dynamic ultrasonic scan of the penis and a photograph of the penis after drug-induced erection. The complaint had lasted for a period of time varying from a minimum of 3 to a maximum of 120 months (average time 23.3 months). 44 patients reported painful erections and 78 patients showed bending of the penis during erection. The pre-treatment dynamic ultrasonic scan of the penis revealed plaques with calcific features in 36 patients, while for the remaining 46 cases the ultrasonic images were compatible with fibrotic thickening. On completion of the 4th treatment session, the patients were given a questionnaire to fill in so that we could obtain a subjective evaluation of the results achieved. All the patients underwent photograph and dynamic ultrasonic scan of the penis (both performed after drug-induced erection, pre- and post treatment). Slight alteration often appeared on the skin of the penis (petechias), which disappeared spontaneously within 48 hours. On completion of the 4th treatment session, 37 patients out of 82 (45%) reported subjective improvement described as "stoppage" in the progression and/or partial regression of the disease" with a filling of a saller size of the plaque on-self examination. As far as concerns pain, this symptom disappeared in 31 out of the 44 patients concerned (70.4%). At the clinical check, based on the ultrasonic scans carried out after ESWT, in 34 cases of 82 (41%), it was possible to note a reduction in the echogenicity or in the size of the treated plaque. In 32 patients (39%) an unchanged plaque was observed, and in 16 case a larger plaque or a calcific evolution was established. For what the bending of the penis concerns, the comparison between the photographs revealed a reduction of the curvature in 24 patients out of 78 (30.7%). Of the 46 patients in whom the disease had non-calcific characteristics, according to the ultrasonic scans, 21 (46%) showed improved disease since in 25 (54%) the treated plaque had stabilized or worsened. In the group of 36 patients with the calcific plaques, 13 (36%) improved while 23 (64%) resulted unchanged or worsened.