The quality of postovulatory oocytes deteriorates over time which impacts the outcome of early embryonic development during human assisted reproductive technology (ART). We and other groups have found that nicotinamide adenine dinucleotide (NAD+), a prominent redox cofactor and enzyme substrate, decreases in both aging ovaries and oocytes. In this study, we found that the NAD+ levels decreased in the postovulatory mouse oocytes during in vitro culture and this decrease was partly prevented by nicotinamide riboside (NR) supplementation. NR treatment not only restored MII oocyte quality but also enhanced early embryonic development potential of postovulatory oocytes via alleviating mitochondrial dysfunction and maintaining normal spindle/chromosome structure. Also, treatment with NR decreased the ROS levels and reduced DNA damage and apoptosis in postovulatory oocytes. Taken together, our findings indicated that NR supplementation increases the oocyte quality and early embryonic development potential in post-ovulatory oocytes which could potentially increase the successful rate in ART.