A 46-year-old Iranian man from Kordestan, Iran, was admitted in Tehran Imam Khomeini hospital complex with complaints of weakness, significant weight loss, and dyspnea during recent 4 months. He had a history of pancytopenia since 8 months ago, and a diagnosis of primary myelofibrosis was established from his bone marrow biopsy revealing fibrosis. His Janus kinase 2 (JAK2) mutation was negative. He was treated with low-dose prednisolone and danazol since 7 months ago. His main complaints included anorexia, weight loss about 15 kg, fever, night sweats, and progressive nonproductive coughs during recent 4 months. He was a smoker, about 20 pack-years, and did not have any previous comorbid diseases. His spleen was resected 4 years ago after an abdominal trauma. On physical examination he was conscious, ill, and cachectic. Oral temperature was 38.4 °C, and respiratory rate was 22 breaths/minute. He had coarse crackle in lungs. No peripheral lymphadenopathy was detected, but the liver was palpable. Laboratory data revealed pancytopenia, elevated alkaline phosphatase (ALP), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Viral markers for hepatitis and human immunodeficiency virus (HIV) were negative. His purified protein derivative (PPD) skin test was negative. His sputum smear for mycobacterium was also negative. On chest computed tomography (CT) scan, diffuse ground-glass opacity of both lungs was seen with centriacinar nodules in upper lobes and bilateral pleural effusion Abdominopelvic CT revealed enlarged liver and accessory spleen, hypodense infiltrative lesions in both kidneys, multiple paraaortic lymph nodes (up to 12 mm), and severe ascites. Lytic destructive lesions in thoracic vertebra 11 (T11) and T12 were also detected. Bone marrow aspiration and biopsy were performed; the aspiration was dry tap, and biopsy showed multiple focal fibrosis and aggregation of epithelioid histiocytes forming granuloma. Reticulin staining revealed marked fibrosis in marrow spaces particularly around granuloma. Percutaneous liver lesion biopsy was also performed, which indicated necrotizing granulomatous inflammation. The patient history and findings of CT scans and tissue biopsies were in favor of disseminated tuberculosis. Therefore, anti-mycobacterium therapy was started including isoniazid, rifampin, ethambutol, and pyrazinamide. Our patient’s dyspnea and appetite improved over the next 10 days. His blood counts increased, and he was discharged after 2 weeks with white blood count (WBC) of 2.9 (103/μL), hemoglobin (Hb) of 10 (gr/dl), and platelet of 140 (103/μL). His final diagnosis was disseminated tuberculosis with secondary myelofibrosis. The anti-TB medications was continued. In follow-up visits after 2 months, his overall clinical status was improved, with 5-kg weight gain and no fever. His blood counts were near normal, including WBC of 3.9 (103/μL), Hb of 12 (gr/dl), and platelet of 177 (103/μL). Anti-TB medications were continued thereafter.