Purpose: The aim of this study was to investigate the diagnostic performance of lesion echogenicity ratios (LER) calculated by image histogram analysis for distinction of malignant and benign breast lesions. Material and methods: A total of 55 patients (mean age, 44 years) with 59 lesions were included. Ultrasound images were analyzed retrospectively. Results: Mean LER values in benign and malignant lesions were 1.63+/-0.41 and 3.1+/-0.87, respectively. The difference between LER values of benign and malignant breast lesions was statistically significant (P<.001). Conclusion: LER can be used as an adjunct ultrasound parameter to differentiate between benign and malignant breast lesions. (C) 2013 Elsevier Inc. All rights reserved.