Previous studies have shown the adverse effects of gestational diabetes on hippocampal neuronal density in animal models. This study was conducted to determine the effect of gestational diabetes on retinal ganglionic cell density, the thickness of the retinal layer and apoptotic ganglionic cell density in 28-day-old of rat offspring. In this experimental study, 10 Wistar rat dams were randomly allocated in control and diabetic groups. Gestational diabetes was induced by 40 mg/kg/body weight of streptozotocin at the first day of gestation, intraperitoneally, dams in control group received an equivalent volume normal saline. At postnatal day 28, six offspring of each gestational diabetes and controls were randomly selected, sacrificed and sections (6 micrometer) were taken from the eye and stained with hematoxylin and eosin. The density of ganglionic cells and the number of dUTP end-labeling (TUNEL)-positive cells were evaluated in 20000 mu m(2) area of ganglion layer of the retina. The ganglionic cells density were reduced (27.4%) in gestational diabetic offspring in compared to controls (22.5 +/- 1.5 vs. 31.0 +/- 0.9, P<0.01). The apoptotic ganglionic cells of retina in interventional group significantly increased in compared to controls (6.74 +/- 0.60 vs. 5.12 +/- 0.26, P<0.02). This study showed that the uncontrolled gestational diabetes can reduce the number of ganglionic cells and increase apoptotic ganglionic cells of retina layer in rat offspring.