Background/aim: Diabetic peripheral neuropathy has been extensively studied and reported, but the number of studies that have investigated diabetes-related changes in the central nervous system are limited, with even fewer studies on the cerebellum. The aim of this experimental study was to perform a histologic analysis of the diabetes-related changes in the cerebellums of diabetic rats. Materials and methods: Twenty Sprague Dawley rats weighing between 200 and 220 g were included in the study. Diabetes was induced in 14 of these rats by a single intraperitoneal injection of 65 mg/kg streptozotocin dissolved in saline, while 6 animals constituted the control group. The induction of diabetes was confirmed by measuring the blood glucose levels in the tail blood with a glucometer. Levels equal to or above 200 mg/dL were considered diabetic. Induction of diabetes failed in 3 animals, who were then excluded from the study. Results: Light and electron microscopic studies revealed that the neurons and glial cells in the diabetic group had degenerative changes, irregularities and disruption in the myelin sheath, disintegration in the presynaptic vesicles, engorged axon terminals, perivascular and mitochondrial swelling, mitochondrial structural changes, and fragmentation of the neurofilaments. Conclusion: Ultrastructural alterations are observed in the diabetic rat cerebellum.