Objective To explore the value of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) for diagnosing prostate cancer and the correlation between IVIM DWI and the Gleason score. Methods The data of multi-b-value DWI of 38 patients with prostate cancer and 32 patients with benign prostate hyperplasia (BPH) were retrospectively analyzed. The D and f values of regions of prostate cancer and BPH were calculated by the IVIM bi-exponential model. The differences of D and f values of regions of prostate cancer and BPH were analyzed. The differences of D and f values of prostate cancer with different Gleason scores were compared and the correlation with the Gleason score was analyzed. Results D and f values of regions of prostate cancer were significantly lower than those of regions of BPH (P<0.05). The D and f values of prostate cancer with different Gleason scores were significantly different (P<0.05). The D value of prostate cancer was negatively correlated to the Gleason score (r=-0.772, P<0.01) and the f value of prostate cancer was negatively correlated to the Gleason score (r=-0.780，P<0.01). Conclusion D and f values can be used for the diagnosis and evaluation of prostate cancer. The IVIM model is expected to predict the aggressiveness and prognosis of prostate cancer from both diffusion and perfusion.