A 69-year-old man had experienced right chest pain for several months. Chest computed tomography (CT) showed a right upper lobe lung tumor and swelling of multiple mediastinal and right hilar lymph node. Three punctures to 4R lymph nodes and two punctures to 11i lymph nodes were performed, using endobronchial ultrasonography. Thirty days after punctures, he was admitted with appetite loss and general fatigue. Chest CT supposed the evidence of mediastinitis and pericarditis. Despite the antibiotics, cardiac tamponade developed on the third hospital day. Pericardial fenestration and pericardial drainage were performed. Gram-positive cocci were identified and Gemella sanguinis was eventually identified as the microbial identification system. Like the former reports, the necessity of surgical procedure for late onset of mediastinitis and pericarditis. caused by EBUS-TBNA was suggested.