Background: Pulmonary hyalinizing granuloma (PHG) is a rare, non-infectious, and benign fibrosing lesion of the lung. It is found with solitary or multiple bilateral nodules and may occur in any lobe. Ocassionally, it mimics metastatic pulmonary malignancy or tuberculosis. The authors report a typical case of PHG that was diagnosed upon histopathological examination via Wedge resection through Video-assisted thoracoscopic surgery (VATS) in a patient with lesions suspecting multiple metastatic lung malignancy. Case summary: A 30-year-old female patient with mild dyspnea of exertion and chronic cough lasting for a year visited our hospital. The patient had no specific underlying disease and was a non-smoker. There were no abnormalities found on physical examination. The chest radiography (X-ray) revealed bilateral multiple pulmonary nodules. Multiple lung nodules in both lung with subcarinal lymphadenopathy was found on contrast enhanced chest computed tomography (CT). Hence, Positron emission tomography (PET) scan was done and multiple hypermetabolic nodules in both lung and fiudeoxyglucose (FDG) uptake at left supraclavicular area were found. Such findings from chest CT and PET-CT strongly suggested metastatic lung malignancy. Accordingly, CT-guided percutaneous needle biopsy was performed and chronic in. ammation was revealed. So, Wedge resection through VATS was performed for diagnosis and deposition of hyaline tissues composed of hypocellular collagen lamellae was the main finding in such histopathological examination through lung biopsy. Hence, this patient was diagnosed as pulmorary hyalinizing granuloma. Conclusions: Based on histopathology and immunohistochemistry, we have diagnosed this patient as pulmonary hyalinizing granuloma. This is a very rare disease and it may present lesion mimicking metastatic lung cancer on radiography. Therefore, clinicians should keep in mind the existence potential of PHG when encountered patients presenting metastatic pulmonary nodules or masses. Key Words: Pulmonary hyalinizing granuloma, Pulmonary nodule, Lung biopsy.