Spinal muscular atrophy (SMA) is a rare autosomal recessive genetic disease caused by Survival Motor Protein 1 (SMN1) gene mutations. Classically divided into three types, SMA is characterized by hypotonia, weakness, and tongue fasciculation in the first 6 months of life in type 1, inability to walk and limb weakness in type 2, and failure to run with proximal weakness in type 3 SMA. With the advent of newborn screening, treating presymptomatic patients with Onasemnogene abeparvovec (OA) is the treatment of choice in some centers worldwide. The incidence of jaundice is high in this age group, with no recommendation to guide the use of OA in newborns with jaundice. To our knowledge, treating an SMA patient with alloimmune hemolytic disease of the newborn (HDN), a relatively common disease in the newborn period, has never been reported in the past. We report our experience with dosing a presymptomatic child with SMA who had neonatal jaundice and hemolytic anemia due to hemolytic disease of the newborn who tolerated the treatment well. To our knowledge, this is the first case to report the safety of this novel treatment for an SMA patient with alloimmune HDN.