Background: Pericardial and pulmonary actinomycosis is a rare disease that remains undiagnosed during life due to a lack of clinical manifestations and a low positive culture rate. Actinomycosis can involve any part of the body. Thoracic actinomycosis is the second most common site after the cervicofacial. Patients with pulmonary actinomycosis usually present with a history of chest pain, cough, fever, shortness of breath on exertion, and sometimes massive hemoptysis. Pericardial involvement has been reported in the medical literature. It is written in line with process case series criteria. Method: From 2008 to 2021, 8 patients, 6 men, and 2 women (mean age 59 y) underwent surgical resection for thoracic lesion initially diagnosed as myofibroblastic tumor on true cut biopsy, but the final histopathologic report revealed actinomycosis. We reviewed preoperative clinical manifestations. Computed tomographic (CT) findings, preoperative true-cut biopsy report, surgical indications, and outcomes. Results: Five patients (62.5%) had poor oral hygiene; 2 patients (25%) had sinusitis, and 1 patient had bronchiectasis (12.5%). Seven patients were symptomatic (87.5%), with hemoptysis, shortness of breath, and weakness. One patient, 12.5%, presented with chest wall mass, chest pain, and fever. The basis of the imaging study (CT thorax). Six patients (87.5%) had CT guided biopsy that revealed a myofibroblastic tumor. In 2 patients (25%), CT scans showed the mass was close to the heart, so a biopsy was not done. We panned a surgical procedure based on the history of hemoptysis and a true cut-biopsy report. Four patients (50%) had a lobectomy, 2 patients (25%) had pericardial resection with a wedge of lung tissues, and 1 patient had chest wall resection enblock with right upper lobectomy. Conclusion:In patients with radiographic findings of pulmonary neoplasm and initial true cut biopsy report showing myofibroblastic tumor, surgery is mandatory. The final histopathology report showed actinomycoses. If the preoperative histopathologic diagnosis is available, then surgery has no role. The ideal treatment is the administration of systemic penicillin therapy. All our patients postoperatively received systemic antimicrobial therapy; they fully recovered and resumed back to everyday life.