Objective: The aim of this study was to determine whether the suggested threshold ADC measurements can be used to characterize benign and malignant breast lesions. Materials and Methods: Sixty two female patients between the ages of 15-64 years (mean age, 44 years) with 49 benign and 25 malignant histopathologically verified breast masses were included in this study. The patients were examined with a 1.5 Tesla system (Optima MR 450W, GE Healthcare, South Carolina, USA) using a bilateral phased-array breast coil. The images were obtained with b values of 0 and 600 mm2/s. The ADC values were calculated for breast masses and for normal fibro glandular tissue.