Objective To analyze the diagnostic efficacy of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) combined with diffusion-weighted imaging (DWI) in prostate cancer (PCa). Methods A total of 94 patients with prostate diseases were selected as study subjects, and divided into PCa group (n=41) and benign prostatic hyperplasia (BPH) group (n=53). The general information of the two groups was compared. The diagnostic efficacy of DCE-MRI and DWI examination parameters in PCa and their correlation with serum prostate-specific antigen (PSA) were analyzed. Results There were statistically significant differences in total prostate-specific antigen (tPSA), free prostate-specific antigen (fPSA)/tPSA, prostate volume (V), prostate-specific antigen density (PSAD), plasma volume fraction (V_p), reflux rate constant (K_ep), volume transfer constant (K^trans), extracellular extravascular volume fraction (V_e) and apparent diffusion coefficient (ADC) between the two groups (P < 0.05). The area under the curve for the combined prediction of PCa using DCE-MRI and DWI examination parameters was 0.924, which was greater than that for individual predictors or the combination of DCE-MRI examination parameters. K^trans, K_ep and V_e were positively correlated with tPSA and negatively correlated with fPSA/tPSA, while V_p and ADC were negatively correlated with tPSA and positively correlated with fPSA/tPSA (P < 0.05). Conclusion The combination of DCE-MRI and DWI has high diagnostic value for predicting PCa, and K^trans, K_ep, V_e, V_p and ADC have certain correlations with tPSA and fPSA/tPSA.