A 35-year-old man presented with a one-month history of fatigue and gingival bleeding. Physical examination of the patient revealed hepatomegaly. Complete blood count (CBC) showed low counts with peripheral blasts. Subsequent bone marrow examination and immunophenotyping confirmed the diagnosis of Acute Myeloid Leukemia (AML-M3), but the patient refused treatment. Fifteen days later, the patient was admitted to hospital with deterioration of his overall condition. He received induction chemotherapy with All Trans Retinoic Acid (ATRA), cytarabine and idarubicin. On the thirtieth day of chemotherapy, chest pain, dyspnea and hemoptysis occurred. Results of laboratory examination were as follows: Hemoglobin: 8.5 g/dL, WBC: 1.4 x 109/L, Platelets: 60 x 109/L, PT 16 s, APTT: 26 s, INR of 1.3. On chest X-rays, ground glass opasities were seen in both lungs. In the parenchymal window on the thorax CT, diffuse bilateral pulmonary alveolar hemorrhaging combined with patchy opacities were observed (Fig. 1). The patient's condition was diagnosed as ATRA-dependent alveolar hemorrhage and steroid treatment was begun (Dexametazon 2 x 10 mg/day). About 15 days after initiation of steroid treatment, coughing and release of sputum started. On chest CT scans, in the parenchymal window, a thick-walled peripheral ground-glass cavitary lesion approximately 27 x 18 mm in size was observed in the left upper lobe. In the left lower lobe mediobazal segment, an atelactasis 7.5 x 4.5 cm in size was found, and in the right lower lobe irregular nodules from 10 mm to 16 mm in size of the area were observed (Fig. 2). Bronchoscopy was performed and bronchial lavage taken. Tuberculosis culture and galactomannan were negative. Serial galactomannan antigen tests on the patient's blood were performed. After 20 days galactomannan was positive and treatment with voriconazole was started (Table 1). One mounth later under voriconazole treatment, the left upper lobe cavitary lesion and lower lobe atelectasis were found to have significantly decreased (Fig. 3). The patient is still being monitored in our clinic.