A 64-years-old female patient was admitted to the emergency department because of fever, dyspnea, and productive cough. The patient had a history of sarcoidosis diagnosed after cosmetic eyebrow tattooing and was receiving daily prednisolone (15-20mg) since the diagnosis and weakly methotrexate (10-15mg) 4 months ago. At the time of admission, the patient was febrile (37.8 C axillary) and had decreased oxygen saturation (89%). The rest of the physical examination was unremarkable except for a bilateral crackle on chest auscultation. By possible diagnosis of pneumonia, the patient received meropenem and ciprofloxacin. The laboratory results revealed a white blood cell count of 4400 (94% of neutrophil), platelet count of 163000, erythrocyte sedimentation rate of 57, creatinine level of 1.3, lactate dehydrogenase level of 800. According to the laboratory results and previous history of receiving prednisolone, a therapeutic dose of cotrimoxazole was added to the antimicrobial regimen to cover pneumocystis jirovecii infection. The primary chest x-ray imaging revealed bilateral infiltration, especially in the upper lobes and hilar lymphadenopathy. The lung high resolution computed tomography (HRCT) showed a bilateral diffuse nodular pattern (figure 1). After 72 hours of antimicrobial treatment, the fever was still present and the patient candidate for fiberoptic bronchoscopy. There was not any endobronchial lesion. Also, there was not any malignant cell or inclusion body reported. The gram staining of the bronchial fluid, polymerase chain reaction (PCR) for tuberculosis, and PCP was also unremarkable. However, the PCR for cytomegalovirus (CMV) was positive. While the PCR for PCP was negative, the cotrimoxazole was discontinued. The quantitative PCR for CMV form blood sample was taken and the result came back as 3.6*103. With the impression of CMV pneumonia, a daily dose of 5mg of ganciclovir was prescribed. After 3 weeks of receiving 5mg/kg of ganciclovir twice daily (600mg daily), clinical symptoms, and dyspnea improved, likewise the radiological findings (figure 2).