PDU is currently being tested as an aid to diagnosing prostate cancer. Our attempt has been to verify its usefulness to improve effectiveness of eight core TR biopsy. Two groups of patients were examined for increased PSA with or without a palpable prostatic nodule. The first group was composed by 52 patients between 55 and 83 years of age (mean 69.57) with PSA values between 0.87 and 94.91 ng/ml (8.085 +/- 14.056) of which 29 (55.75%) showed a palpable nodule. All patients underwent prostatic eight core TR echobiopsy. The second group was composed by 56 patients between 49 and 84 years of age (mean 69,19) with PSA values between 1.14 and 59.7 ng/ml (8.74 +/- 12.977) of which 33 (58.97%) showed a palpable nodule. This group of patients underwent a PDU just before TR biopsy in order to assess prostatic blood supply and locate possible alterations. Prostatic volume in both groups was never higher than 50 cc. Of the first group 25 patients (48.08%) were prostate cancer positive. Of the second group 31 patients (55.36%) were positive to a biopsyfor prostate cancer. In addition 22 out of the 31 showed a palpable nodule and vascular irregularity. PDU is being tested in order to reduce the number of biopsies and tissue samplings. The above results (tests carried out by the same operator with two homogeneous groups of patients) show how PDU was useful in diagnosing a higher number of prostate cancers. We could therefore safely conclude that the use of PDU in association with TR biopsy greatly increases diagnostic sensitivity and specificity.