Objective To explore the diagnostic value of Multiparametric magnetic resonance imaging (mp-MRI) quantitative parameters combined with serum prostate cancer antigen-2 (EPCA-2) and prostate specific antigen (PSA) in prostate cancer (PCa) with capsular invasion (ECE). Methods The clinical data of 106 patients with PCa admitted to our hospital from July 2021 to June 2023 were retrospectively analyzed. All patients underwent MRI plain scan, diffusion weighted imaging (DWI), dynamic contrast-enhanced scanning (DCE-MRI), and the expression of EPCA-2 and PSA in serum were measured. According to the pathological results, ECE patients were divided into ECE group and non-ECE group, mp-MRI quantitative parameters ［apparent diffusion coefficient (ADC), elution coefficient (Kep), transfer constant (Ktrans), vascular gap volume fraction (Vp), EES volume fraction (Ve)］, serum EPCA-2 and PSA levels were compared between the two groups. The diagnostic value of the combined quantitative parameters of mp-MRI and serum EPCA-2 and PSA level for ECE in patients with PCa was analyzed. Results There were 106 lesions in 106 PCa patients, including 45 cases with ECE and 61 cases without ECE. The ADC value of ECE group was lower than that of non-ECE group, and the K trans value, serum EPCA-2 and PSA levels were higher than those of non-ECE group (P＜0.05), there was no statistical difference between the two groups in Kep, Vp and Ve (P＞0.05). Logistic regression analysis showed that mp-MRI quantitative parameters (ADC, Ktrans), serum EPCA-2 and PSA expression were associated with ECE in PCa patients, and may be risk factors for ECE (P＜0.05). ROC curves were plotted. The results showed that ADC, Ktran, serum EPCA-2 and PSA alone or in combination were valuable in the diagnosis of ECE, and AUC values were all>0.70. Conclusion MP-MRI quantitative parameters combined with serum EPCA-2 and PSA expression are valuable in the diagnosis of ECE in PCa patients