High-frequency real-time sonography has enhanced accuracy in the diagnosis of scrotal abnormalities. Results of 48 scrotal scans of 92 testes are presented. There were 22 testicular lesions, nine seminomas, four embryonal cell carcinomas, one case of metastatic prostatic carcinoma, one benign "keratin cyst," three testicular infarcts, three atrophied testes, and one case of testicular torsion. Hypoechoic tumors and infarcts have a similar appearance. Extratesticular abnormalities included spermatoceles, varicoceles, epididymitis, hydroceles, and a scrotal hematoma. Sonography accurately distinguished between testicular and extratesticular masses in all cases in this series and pathologic correlations were obtained for all testicular masses. Simultaneous real-time contact scanning and palpation facilitated accurate diagnosis.