Leukemoid reactions following surgery are commonly caused by infections or tissue injury. Management is directed towards underlying condition and cytoreduction is not indicated. Chronic myelo-monocytic leukemia (CMML) is a clonal hematological malignancy characterized by persistent monocytosis and overlapping features of myelodysplastic and myeloproliferative neoplasms.In this case report we describe a 51-year-old Hispanic female without any significant prior medical history, who underwent a cholecystectomy for calculous cholecystitis. Post-operative course was complicated by hyperleukocytosis leading to splenic infarction and intracranial hemorrhage. Further investigations led to a diagnosis of CMML-2. A literature review of patients with CMML who developed post-operative leukocytosis and leukostasis (POLL) is presented.Case high lights two critical points: Post-operative hyperleukocytosis with leukostasis can be the first presentation of CMML Rapid diagnosis and institution of cytoreductive therapy with hydroxyurea is critical to avoid high morbidity and mortality.