Objective To evaluate the ability of the intravoxel incoherent motion (IVIM) MRI to differentiate prostate cancer from benign tissue, and to compare its diagnostic performance with conventional diffusion-weighted imaging (DWI). Methods Conventional MRI and IVIM MRI (b=0～800s/mm2 ) were performed in 36 patients. Regions of interest were drawn in cancerous tissue of 20 patients and benign tissue of 16 patients proved by transrectal ultrasound guided prostate biopsy and fitted to a monoexponential model [yielding the apparent diffusion coefficient (ADC)] and the IVIM signal equation (yielding the diffusion constant D, the pseudodiffusion coefficient of perfusion D* and the perfusion fraction f). Mann-Whitney tests were performed to evaluate statistical differences of ADC, D, D* and f between prostate cancer and benign tissue. Receiver operating characteristic (ROC) analysis were utilized for diagnostic performance of ADC and D. Results ADC values and D values were significantly lower (P＜0.01) in cancerous tissue. Area under the curve (AUC) of ADC and D was 0.859 and 0.961, respectively. The best diagnostic threshold, sensitivity and specificity for ADC was 1.24×10-3mm2 /s, 93.8% and 65.0%, meanwhile, 0.95×10-3mm2 /s, 93.8% and 85% for D. Conclusion D of IVIM DWI provides better diagnostic performance than ADC of conventional DWI, IVIM DWI holds potential for investigation of prostate cancer.