We compared the ultrasonic and histologic findings in 25 patients with benign prostatic hyperplasia (BPH) who underwent retropubic subcapsular prostatectomy. Preoperative ultrasonograms showed a fine echogenic pattern in one case, a rough echopenic pattern in four cases, and a combination of these patterns in 20 cases. In cases exhibiting a mixed pattern, we analyzed each region individually. Ultrasonic and histologic findings were compared in a total of 45 regions. In the 21 regions with a fine echogenic pattern, 14 regions corresponded to those with complicated hyperplastic glands, one region with small cystic atrophic glands, and six regions with a mixture of the two types on histology in observation. In the 24 regions with a rough echopenic pattern, 20 regions corresponded to those with large cystic atrophic glands and an equal volume of large and small cystic atrophic glands were found in the other four. Thus, the echogenic structures observed in patients with BPH were determined by the presence of complicated hyperplastic glands and small cystic atrophic glands.