Aspartame is an artificial sweetener and flavour enhancer in low-calorie, with sweetness about 200 times higher than sugar. The present study aims to declare the effect of aspartame on the histological and immunohistochemical structures of the skin in Wistar albino rat neonates. Twelve pregnant female Wistar-albino rats were separated into two groups, a control and an experimental group (n = 6). The first group was orally administered a daily dose of saline solution (0.5ml) free from the 4^th day of pregnancy till birth. The second group was orally administered 40mg aspartame/kg body weight for the same period. Samples from the dorsal abdominal  skin of one day-old  neonatal rats were fixed in 10% buffered neutral formalin and prepared routinely for histopathological and immunohistochemical investigations. Other samples were taken immediately, frozen and prepared  for flow cytometric investigation of annexin V. Compared with the control group, the skin of aspartame treated neonatal rats showed a significant decrease (P<0.05) in the epidermal and dermal thickness as well as hair follicle depth. The epidermis appeared foliated with obvious hypertrophied cells; other dispersed cells had pyknotic nuclei and vacuolated cytoplasm. The dermis showed less condensed connective tissue, degenerated sebaceous glands and scarcely irregular hair follicles. The immunohistochemical investigations of aspartame neonatal rats showed intense positive reactions for Caspse-3, P53 and vascular endothelial growth factor (VEGF) but a negative to weak reaction for Caspase-7 and CK17 antibodies. Furthermore, the flow cytometric analysis of the annexin V revealed a significant increase in the apoptotic area corresponding to upper right (UR) and lower right (LR) area. In conclusion, the consumption of aspartame by mother rats during gestation leads to remarkable histological lesions and increased risk of apoptosis in the skin of their neonatal pups.