Transrectal ultrasound (TRUS) offers a valuable complement to digital rectal examination (DRE) in diagnosing prostate diseases. However, in case of prostatitis syndromes, contradictions are found with regard to characteristic ultrasound features in these patients. Therefore we sought for better imaging techniques. This paper describes a study on the automated analysis of ultrasonographic prostate images (AUDEX). With image processing, in the present study, tissue characterization is performed to predict the probability of the presence of inflammated prostate tissue. This technique already proved its validity in patients with prostate cancer. During prostate examinations, images were recorded with clear indication of the puncture position. Only patients with an unambiguously inflamed or noninflamed benign histologic result were included. Evaluation showed that a sensitivity of 90.6% and a specificity of 64.2% was reached. Finally, the prospective positive and negative predictive value for prostatitis was 50.0% and 94.6%, respectively. This means that AUDEX predicts the diagnosis 'prostatitis' in a large number of patients with no infection. In case of prostatitis, however, this prediction is almost always right.