In the report we refer to our experience as regards the role of transrectal ultrasonography in the early diagnosis of prostatic heteroplasia based on the results obtained by a research led from January 1991 to January 1995 on 1185 dysuria patients who have been subjected also to a rectal exploration and a serous dosage of PSA. Among the 306/1185 (25.8%) of the patients subjected to prostatic echoguided biopsy sec. Hodge in 238 (77.7%) a hypoechogenic zone on behalf of the periphery of the prostatic parenchyma has been reported. The histological result has pointed out the presence of adenocarcinoma in 81 (26.4%) patients; of benign prostatic hypertrophy in 196 (64%); of acute and/or chronic non specific phlogosis in 26 patients (8.4%) and granulomatosis prostatitis in 3 (1%). The sensibility, the specificity and the diagnostic efficiency of the transrectal ultrasonography in the diagnosis of prostatic heteroplasia have resulted equal, respectively to 100%, to 30.2% and to 48.6%. In 122 patients (66%) the hypoechogenic zone was not pathognomonic of prostatic heteroplasia. Definitely, considering the high sensibility in opposition to the insufficient specificity of the echography, it is our future intention not submit to prostatic biopsy those patients who show only a hypoechogenic zone in absence of pathology EDR and PSA but to monitor them through quarterly clinic checks.