Fifty-nine eyes suspected of having an intraocular foreign body (IOFB) were independently evaluated by ultrasonic and radiologic localization techniques. Comparison of the results of surgically or visually confirmed cases revealed agreement in 50 (85%) of the eyes. Of the nine (15%) cases of disagreement, five were found to have an IOFB—three identified only by x-ray and two identified only by ultrasound. In four cases, the absence of an IOFB, which was thought to be present by the ultrasound study, was correctly diagnosed by x-ray films. The combined use of ultrasound and a pulsating electromagnet confirms the diagnosis of a nonvisualized magnetic IOFB. From this study it appears that ultrasound is a valuable complementary technique to x-ray localization of orbital foreign bodies, but does not substitute for radiographic evaluation.