This study compares the results of a new computer assisted evaluation program of sonographic images of the prostate with the histological examination of the operative specimen. This computer program is based on the fact that the human eye is not capable of distinguishing picture distribution points which differ in higher than second order statistics. The sensitivity of the method was 89%, the specificity 86% and the diagnostic accuracy 88%. The results are discussed by comparing them to results of transrectal sonography and digital palpation as reported in the literature.