Supplementation with vegetables and fruits derived products plays a unique role in the protection against various diseases as it has many flavonoids that provide several health benefits. Exposure to nano-rich diesel exhaust particles (NRDEPs) especially during developmental stages may be induce oxidative damage and trigger apoptosis in different fetal organs. So, the present study aims to evaluate the hepatic protective effect of quercetin against toxicity of NRDEPs in albino rat fetuses. A total of forty timed-pregnant albino rats were randomly assigned to four different groups. The first group served as negative control and received normal saline, dams of the second group received 100 mg/kg of quercetin, and those of the third group received 20 mg/kg of NRDEPs, the fourth group received 100 mg/ kg of quercetin two hours before NRDEPs exposure. All dams were received their corresponding doses from 5th day of gestation till to 20th day. The animals were received caesarean section at end of gestation and fetal liver was removed for immunohistochemical examination together with biochemical and molecular studies. Our results indicated that maternal pretreatment with quercetin significantly ameliorated the oxidant / antioxidant disturbance (MDA, GSH, GST and PON) induced by NRDEPs, down regulated the apoptotic genes (Bax and caspase-3) expression and reduced DNA fragmentation. In conclusion, quercetin could suppress the oxidative stress and apoptosis induced by nano-rich diesel exhaust particles in fetal liver without side effects. We suggest that quercetin may be useful in combating cytotoxicity caused by NRDEPs.