We studied the findings on color Doppler sonography in five men with testicular ischemia (three with acute testicular torsion and two with testicular infarcts after herniorrhaphies). In all five cases, no intratesticular blood flow was identified on the symptomatic side, while normal blood flow was evident on the opposite side. In the three cases of acute torsion, no gray scale sonographic abnormalities were seen, and in the two cases of postoperative infarction, the abnormalities were nonspecific. These findings suggest that color Doppler sonography can be used to show decreased blood flow in cases of acute testicular ischemia and that it may have a role in evaluating patients with suspected testicular torsion.