We aimed to determine whether cortical stiffness (CS) values obtained by point shear wave elastography (pSWE) were increased in patients with diabetic kidney disease (DKD) according to increased disease stage and to determine the parameters associated with CS value in the same patient group. A total of 120 patients with Type-II diabetes mellitus who developed DKD and 22 healthy controls were included in the study. In addition to routine laboratory tests and renal ultrasonography (USG), CS levels were measured using pSWE. Carotid intima-media thickness (IMT) and aortic-IMT values were measured. Patients were grouped according to DKD stage (Stage I-II-III-IV-V), then the control group was added and, the six groups were compared within themselves. Renal CS values were found to be significantly higher in all stages of DKD than in the control group and were found to be increased in accordance with the increase in DKD stage (P < 0.05). When receiver operating characteristic curve analysis was performed for determining patients with Stage IV-V DKD, it was found that AUC was 70% for parathyroid hormone (PTH), common and internal carotid-IMT, NT-proBNP, cortical thickness, and CS values. It was found that cortical thickness and PTH levels were independently associated with renal CS in DKD patients and independently determined the risk of increased CS (>9.0 kPa) in DKD patients (P < 0.05). Renal CS is increased with increasing DKD stage and this is closely related to decreased cortical thickness and serum PTH levels. Renal CS measurement should be used during follow-up of a patient as part of the renal USG.