Abstract Objective: This study aimed to describe the effect of prophylactic phototherapy in the treatment of infants with Neonatal Hemolytic Disease. Method: A retrospective cohort study was carried out with 199 RhD-positive infants, born to RhD-negative mothers, alloimmunized for RhD antigen, between January 2009 and December 2018. Results: The incidence of exchange transfusions in the study population was 9.5%, with a mean maximum bilirubin value of 11.3 mg % (± 4.3mg %). Bilirubin’s maximum peak was achieved with a mean of 119.2 life hours (± 70.6h). Conclusions: The low incidence of exchange transfusion, the extended maximum bilirubin peak for later ages, and the low mean of the maximum bilirubin values may indicate a positive effect of prophylactic phototherapy in the treatment of this disease. Further studies must be carried out to confirm these findings.