Thirty patients presenting through the Breast Screening Programme with impalpable breast abnormalities clearly visible on ultrasound, underwent non-invasive ultrasound localization. The patient was scanned so that the ultrasound abnormality lay below the probe and the skin at this site marked with a skin marker. In all cases the abnormality was easily identified and removed at surgery. All the surgical biopsies contained either a carcinoma (17 cases) or fibroadenoma (13 cases). This non-invasive technique is a simple and accurate method for localizing small ultrasonically visible breast abnormalities.