Objective To investigate the diagnostic value of two-phase contrast-enhanced CT combined with the plasma level of soluble cluster of differentiation 14 subtype (presepsin) for acute pyelonephritis (APN).Methods The clinical data of 95 patients with urinary tract infection admitted to The First People's Hospital of Fuzhou from March 2019 to May 2020 were retrospectively analyzed. According to the clinical diagnosis, the patients were divided into the non-APN group (n = 42) and the APN group (n = 53), and those with APN were subdivided into the non-critical group (n = 34) and the critical group (n = 19) according to the severity of the disease. The general data and the plasma level of presepsin were compared between the APN group and the non-APN group, and the plasma level of presepsin was also compared between the critical group and the non-critical group. The consistency between the findings of the two-phase contrast-enhanced CT and the clinical diagnosis was analyzed, and the diagnosis made via the findings of the two-phase contrast-enhanced CT combined with the plasma level of presepsin was compared with the clinical diagnosis as well. The receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic value of two-phase contrast-enhanced CT combined with the plasma level of presepsin for APN.Results There was no difference in sex composition, age, duration of urinary tract infection and body mass index between the APN group and the non-APN group (P > 0.05). The plasma level of presepsin in the APN group was higher than that in the non-APN group (P < 0.05), and the plasma level of presepsin in the critical group was higher compared with that in the non-critical group (P < 0.05). The consistency between findings of the two-phase contrast-enhanced CT and the clinical diagnosis was fair (Kappa = 0.725, P = 0.012), while the consistency between the diagnosis made via the findings of the two-phase contrast-enhanced CT combined with the plasma level of presepsin and the clinical diagnosis was good (Kappa = 0.798, P = 0.005). ROC curve analysis revealed that the sensitivities of two-phase contrast-enhanced CT, the plasma level of presepsin, and their combination for diagnosing APN were 88.68% (95% CI: 0.767, 0.923), 79.25% (95% CI: 0.673, 0.865) and 93.34% (95% CI: 0.634, 0.978), with the specificities being 73.81% (95% CI: 0.528, 0.835), 71.43% (95% CI: 0.501, 0.827), and 90.48% (95% CI: 0.696, 0.982), and the areas under the ROC curves being 0.812 (95% CI: 0.719, 0.885), 0.717 (95% CI: 0.615, 0.804), and 0.924 (95% CI: 0.851, 0.968), respectively.Conclusions Two-phase contrast-enhanced CT and the plasma level of presepsin can be used to diagnose APN, and the combination of the two exhibits a higher diagnostic value.