Noninvasive discrimination of mediastinal lymph nodes (MLN) is crucial for management of cancer patients such as those with non-small cell lung carcinoma. This study aims at investigating the value of IVIM diffusion parameters (D, D*, and f) as well as ADC for discrimination of malignant and benign MLN. A total of 91 MLN from 35 patients with histopathologic proven lesions were studied. D and f of malignant mediastinal lymph nodes were significantly different from those in the benign ones. The combination of f and D produced the highest diagnostic performance as evaluated by a receiver operating characteristic (ROC) analysis.