Sir, A 26-year-old man presented to us with chief complaints of fever, cough, and dyspnea since 15 days. There was no history of hemoptysis, chest pain, orthopnea, palpitations, or edema feet. A more detailed history was negative for environmental or medication exposure. Past history was insignificant for any prolonged illness. There was no history of any addiction. On examination, pulse was 100/min, regular. Respiratory rate was 18/min, and the temperature was 38.6 °C. JVP was not raised. Auscultation of the lungs revealed bilateral, diffuse rales. Cardiovascular system examination was normal. Investigations revealed, Hb of 11 g %, Total leucocyte count (TLC) was 52,000, DLC revealed polymorphs of 15 %, eosinophils 78 %, lymphocytes 6 %, monocyte 1 % (Fig. 1). Peripheral smear was devoid of any blasts. Absolute eosinophil count was 38,000/mm3 (normal 52–250 mm3). Platelet count was 250,000/mm3. The bone marrow aspiration revealed eosinophilic proliferation without any blasts (Fig. 2). The blood biochemistry was normal. CXR revealed bilateral haziness. HRCT of thorax revealed bilateral ground glass opacities (GGOs) (Figs. 3, ,4).4). Two dimensional (2D) echo was normal. ABG revealed partial pressure of oxygen, 68 mmHg; partial pressure of carbon dioxide, 29 mmHg; and pH, 7.50. SpO2 was 84 % while patient was breathing ambient air. Cultures of sputum, blood, and urine were negative for bacteria, mycobacteria, fungi. ESR was 24 mm in first hour. Peripheral smear examination for parasites and microfilaria was negative. Fig. 1 Peripheral smear (Leishman stained ×10 view) showing eosinophilia Fig. 2 Bone marrow slide (Leishman stained ×40 view) showing eosinophilic predominance Fig. 3 Coronal CT image shows bilateral, diffuse and patchy ground glass opacity (arrows) Fig. 4 Axial CT image showing bilateral ground glass opacity Patient was treated with empirical antibiotics, NIPPV, oral corticosteroids (Tab. prednisolone 60 mg/day). Patient’s breathlessness decreased dramatically on the third day. NIPPV was discontinued. He was maintaining O2 saturation of 98 % in ambient air. ABG became normal. A bronchoalveolar lavage was done, which revealed, total cell count of 132 × 103 with 22 % eosinophils. In the first week after treatment TLC came down to 15,000/mm3, with 25 % eosinophils. AEC was 4,000/mm3. Repeat HRCT showed partial clearing of the GGOs. Fever, cough and dyspnea subsided. A diagnosis of acute eosinophilic pneumonia with eosinophilic leukemoid reaction was made. By the end of second week, TLC was 10,000/mm3. DLC revealed 12 % eosinophils. AEC was 1,100/mm3. Patient was discharged with a tapering dose of prednisolone, and was advised follow up after two weeks.