Background: the cornea exhibits viscoelastic properties, which give it the quality of hysteresis. Corneal hysteresis is an important indicator of the biomechanical properties of the cornea. Aim: to compare the biomechanical properties of the cornea in patients having diabetes mellitus and age matched normal individuals as regards to corneal hysteresis (CH), corneal resistance factor (CRF), Corneal compensated IOP (IOPcc) and Goldman- correlated IOP (IOPg). Patients and Methods: A total of 200 eyes of 100 patients were enrolled in our study. Patients were selected from Ophthalmology outpatient clinics in Minia Health Insurance Hospital – Ophthalmology department. The type of our study is a case-control one. Patients were divided into two equal groups: Group A: included 50 patients (100 eyes) of age matched normal individuals. Group B: included 50 patients (100 eyes) having type 2 diabetes mellitus. Results: mean CH in control group was 9.8±1.3 mm Hg in comparison to mean CH in diabetic group which was 11.9±1.4 mm Hg, which was statistically significantly higher in diabetic patients when compared to control group, (P value = 0.<001). Conclusion: the corneal biomechanics in diabetic group are significantly higher compared with those of the control group.