Introduction: Mammography is commonly regarded as the single most important tool for screening and for early detection of breast cancer. However it is not generally recommended for women under 40 years of age and in those taking hormone replacement therapy as the increased density of the breast parenchyma may make mammography more difficult to read and interpret. The limitations of mammography have spurred attempts to find new techniques that can be used either separately or in conjunction with mammography. Purpose: The aim of this study was to quantify the clinical value of using electrical impedance scanning (EIS) or Trans Scan as an adjunct to mammography in order to identify cancerous tissue based upon its inherent altered local dielectric properties. Methods and Materials: The patients were examined using Trans Scan (Trans Scan Medical, Ltd., distributed by Siemens AG. The study population was derived from patients with suspicious breast lesions categorized as BIRADS 3 or 4 detected during mammography or ultrasound. Results: Fifty-three women with 53 mammographically and/or sonographically suspicious findings were examined using EIS. With respect to the histopathological findings (15 malignant and 38 benign lesions) 13 of 15 (86.6% sensitivity) malignant lesions were correctly identified using EIS whereas, 33 of 38 (81.5% specificity) benign lesions were correctly identified. Negative and positive predictive values of 93.9% and 65% were observed respectively. Two benign lesions were correctly identified in a dense breast. The smallest lesion detected in this study measured 20 x 14 mm, which was an infiltrating ductal carcinoma. Conclusion: Electrical impedance scanning as an adjunct to mammography or ultrasound in classifying suspicious lesions is promising because it increases the sensitivity for cancer detection and may reduce biopsy of equivocal lesions. The additional use of EIS with negative predictive value of 93.9% may be useful to exclude some benign lesions from further diagnostic or invasive procedures. Artifacts, such as signals from superficial skin lesions, poor contact and bubbles are currently a limitation