Immune hemolysis is one of the adverse effects that can occur following solid organ transplantation. Understanding the clinical settings and the various causes is necessary for prompt diagnosis and appropriate management. One such condition is passenger lymphocyte syndrome (PLS). This case report describes the case of a 27-year-old male renal allograft recipient of the B-positive blood group who received a kidney from an O-positive donor. Postoperatively, the patient showed declining hemoglobin (Hb) level and was transfused with B-group packed RBCs (PRBCs), following which there was steep fall in Hb level. A request for PRBCs was sent to the blood bank and this time cross-match with B-group PRBCs showed incompatibility. The patient's RBCs were found to be strongly DAT (direct anti-globulin test) positive and the eluate showed the presence of anti-B with a titer of 32. Thus, diagnosis of probable PLS was made. The patient was managed with methylprednisolone, plasmapheresis and O-group PRBCs. Gradually his condition improved and was discharged in stable condition.