Background: Diabetes is a rapidly-growing global health problem with a significant impact on morbidity and mortality due to diabetes-related complications. Objective: The purpose of this study was to assess the impact of type II diabetes on the central corneal thickness (CCT) and intraocular pressure (IOP). Patients and Methods: This prospective case-control study was performed at the ophthalmic department of Al-Zahraa University Hospital. It was conducted on 30 participants with type II diabetes and 10 healthy control (both eyes were included). Diabetics were categorized into 3 groups, diabetics without retinopathy, with non-proliferative diabetic retinopathy (NPDR) and with proliferative diabetic retinopathy (PDR).Each group contained 10 participants. Complete ophthalmic examination was done for all participants including, visual acuity, slitlamp, fundus examination, measurement of IOP and CCT. Fundus photography and measurement of glycosylated hemoglobin A1c (HbA1c) were done for diabetics. Results: Diabetics with PDR exhibited significantly higher IOP and CCT values compared to other groups. The IOP was significantly correlated with CCT and with the duration of diabetes. Conclusion: Diabetics with PDR had a significantly elevated IOP and thicker corneas than normal subjects. These data emphasize the importance of considering CCT measurements in diabetics for proper interpretation of IOP.