Objective[|]The aim of this study was to evaluate the role of diffusion-weighted magnetic resonance imaging (dMRI) in differentiating between diffuse malignant and benign pleural thickening in asbestos-related pleural diseases.[¤]Materials and Methods[|]Sixty-two patients were included in the study. Thirty-two had a benign form and 30 had malignant pleural mesothelioma (MPM). The patient files and records belonging to those who underwent dMRI on a 1.5 T MR system between May 2014 and January 2016 in our clinic were examined retrospectively. The dMRI was performed with 0, 500, and 1000 mm2/s b-values. The apparent diffusion coefficient (ADC) map was generated, and means ADC values were determined from measurements of pleural thickening.[¤]Results[|]The mean ADC values were 1.94±0.09×10-3 mm2/s and 0.84±0.05×10-3 mm2/s in benign pleural disease and MPM, respectively. The mean ADC value in the malignant group was significantly lower than in the benign group (p<0.05).[¤]Conclusion[|]Our results show that dMRI and ADC values are useful for differentiating between benign and malignant pleural thickening in asbestos-related pleural diseases. dMRI gives clues for the interpretation of whether pleural thickening is benign or malignant and can assist in the early detection of MPM.[¤]