We compared surgical and pathological findings to those of preoperative scrotal ultrasonography in 50 consecutive patients undergoing surgical exploration for testicular trauma, tumors or benign atraumatic conditions. An inhomogeneous parenchymal echo pattern was the single most reliable predictor of a parenchymal abnormality. Large scrotal hematomas may preclude adequate visualization of the parenchyma and early testicular torsion may exhibit a normal parenchymal echo pattern. Except for early torsion, no false negative predictions of the state of the parenchyma were made.