Hyperhemolysis syndrome (HHS) is a rare and severe posttransfusion complication characterized by the destruction of both recipient and donor red blood cells. The underlying mechanism of HHS is not fully understood and proper management can be difficult. Furthermore, there are few reports regarding HHS in pregnancy. We report on the development and management of HHS in a pregnant woman with known compound sickle cell disease (SCD)/β⁰-thalassemia and alloimmunization after transfusion of packed red blood cells (PRBC). We aim to raise awareness on this diagnostically challenging and life-threatening type of hemolysis with this report, and to stress the need to consider the diagnosis of HHS in SCD patients with progressive anemia despite PRBC administration.