Two hundred and three male patients underwent transrectal ultrasonography(TRUS) examination because of palpable nodule or hard consistency of the prostate. Of these, 56 of 65 (86.2%) digital rectal examination (DRE)-abnormal and 34 of 138 (24.6%) DRE-normal patients received transrectal sonoguided core needle biopsy. Among the DRE-abnormal patients, 18 (32.1%)had prostatic adenocarcinoma by biopsy with 2 additional patients who had initial negative biopsies eventually found to have cancer by transurethral resection of the prostate. In contrast, only 2 (5.9%) of 34 DRE-normal patients had cancers that were both hypoechoic and peripheral zone located. In 13 patients with transitional zone located lesions (hypoechoic 9, isoechoic 4),none had cancer. Of 27 patients who had normal DRE and unsuspected TRUS and received transurethral prostatectomy because of bladder outlet obstruction, 4 (14.8%) had cancer. In this study, hypoechoic lesions were found in 68 patients, among them 60 (88.2%) underwent biopsy but only 14(23.3%) had cancer. From the results of this study, we concluded that TRUS can be a useful adjunct of DRE in detecting prostatic malignancy, especially when there has been an abnormal DRE, but its role on a digitally normal prostate requires further evaluation. Serum prostate-specific antigen can be an additional indicator to increase the prostate cancer detection rate.