Purpose <p>To report a case of two monozygotic twin pregnancies after a single frozen blastocyst transfer of embryos that underwent preimplantation genetic testing.</p> Methods <p>A 38-year-old woman pursued in vitro fertilization with preimplantation genetic testing for Gaucher’s&#xa0;disease.</p> Results <p>The patient underwent a natural frozen embryo transfer of a single unaffected, euploid blastocyst, which resulted in a nonviable monozygotic monochorionic-diamniotic twin pregnancy. From the same oocyte cohort, she underwent another natural frozen embryo transfer of a single unaffected, euploid blastocyst, again resulting in a nonviable monozygotic monochorionic-diamniotic twin pregnancy. Cytogenetic evaluation of the products of conception from both pregnancies was concordant with the preimplantation genetic testing results of both embryos.</p> Conclusion <p>Recurrence of monozygotic twinning after single-embryo transfer is exceedingly rare. Further clarification is needed regarding the risk factors leading to monozygosity in assisted reproductive technology.</p>