88 patients with ultrasonically detected breast tumours were examined at the Department of Obstetrics and Gynaecology of the Technical University Aachen (RWTH) in the context of a prospective study. Ultrasonic contour characteristics and marginal zone displacement properties were evaluated with regard to their usefulness as criteria for detecting malignancy. using a highresolution hand-held 10 Mhz scanner. With regard to marginal zone displacement as a sign of benignancy, a sensitivity of 67.6% and specificity of 86.3% were found (positive and negative predictive value reaching 89.3% and 86.3%, respectively). A sensitivity of 84.3% and specificity of 86.5% could be demonstrated when an ill-defined, jagged contour was taken as a sign of malignancy. A well-defined, smooth contour resulted in a sensitivity and specificity of 62.2% and 100%, respectively, when used as criterion for benignancy. No clear indication could be found to support the use of an ill-defined but smooth contour as a sign of benignancy. 56.3% showing the aforementioned characteristic were benign, the rest (43.7%) were malignant neoplasias. The evaluation of ultrasonic contour characteristics and marginal zone displacement properties are hence fundamental criteria to augment other characteristic tumour signs in the ultrasonic diagnosis of breast pathology.