Acute leukemia during pregnancy is rare (1 for 100000 pregnancies). The association of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) is known as the best therapy in standard-risk acute promyelocytic leukemia (APL). We describe the first case of a pregnancy with ATRA and ATO reported in the literature. In March 2018 at the University Hospital of Besançon, a 22-year-old woman was diagnosed with APL at 14 weeks of gestation (WG). She received a total of 2160 mg of ATRA and 930 mg of ATO between 14 and 35 WG. The mother's cytological remission was very fast. No maternal or fetal complications occurred during pregnancy. The pediatrics outcomes were good. Many case reports about ATRA exposure during the second and third trimesters report no serious adverse effect for pregnancy. ATO is teratogenic, genotoxic, and carcinogenic and passes through the placenta. Fetal exposure seems to be associated with bad pregnancy outcomes (preterm delivery, decreased birth weight, and fetal loss) and with lung diseases in young adults. No clinical trial is obviously possible, and the only data available are environmental exposure or animal studies. This case report may help medical teams to make hard decision for a treatment of APL during pregnancy.