Acute myeloid leukemia (AML) is a malignant hematologic disorder characterized by bone marrow failure and an increased risk of hemorrhagic complications due to thrombocytopenia, coagulopathy, and hyperfibrinolysis. While AML is associated with bleeding tendencies, massive spontaneous hemothorax (SH) is an exceedingly rare and often fatal manifestation. We report the case of a patient who presented with acute chest pain, dyspnea, and hemodynamic instability, ultimately diagnosed with AML-associated hemothorax. Imaging confirmed a large pleural effusion, and pleural fluid analysis revealed a hematocrit consistent with hemothorax. Bone marrow biopsy established a diagnosis of acute myelomonocytic leukemia (AML M4, FAB classification) with myelodysplasia-related changes (WHO classification). Management included urgent tube thoracostomy, correction of coagulopathy, and fluid resuscitation, with surgical intervention considered based on bleeding progression. Despite supportive measures, the prognosis in AML-associated hemothorax remains poor due to the underlying malignancy and hemorrhagic complications. During disease progression, the development of spontaneous hemopericardium further worsened the prognosis, leading to severe hemodynamic deterioration and increased mortality risk. This case underscores the importance of early recognition, rapid diagnosis via ultrasound and CT imaging, and a multidisciplinary treatment approach involving hematologists, intensivists, and thoracic specialists. Given the rarity of this complication and the absence of standardized guidelines, further studies are needed to refine diagnostic and therapeutic strategies for AML-related hemothorax.