Understanding reproductive development effects and transferable properties to next generation of zinc oxide nanoparticles is necessary for prevention of its potential risks. To accomplish this, rats were exposed to zinc oxide nanomaterials (500 mg/kg bw) of less than 100 nm beginning 2 weeks before mating to postnatal day 4. In addition, body distribution of zinc concentration was evaluated in dams and offspring. Rat treated with nano-zinc oxide showed reduced number of born/live pups, decreased body weights of pups and increased fetal resorption. Zinc oxide nanomaterials were also distributed to organs such as mammary tissue of dams and liver and kidney of pups. These results indicate that zinc oxide nanoparticles-exposure before and during pregnancy and lactation could pose health risks to pregnant women and their fetus.