Percutaneous needle aspiration has been widely used in the diagnosis of pulmonary lesions, because it is a fairly simple procedure with good diagnostic accuracy and low complication rate. Among its complications, the spread of malignant cells along the needle tract is rare but serious one. We report a case of chest wall implantation of lung cancer after the percutaneous fine needle aspiration biopsy. A 57-year-old man had undergone a right upper lobectomy for squamous cell carcinoma [T2N0M0] of the lung, 3 months after the operation, a growing mass, located far from the previous thoracotomy incision, developed on the right anterior chest wall where the diagnostic thin needle biopsy had been performed before the lobectomy. A wide excision of the chest wall mass was performed, and permanent histology showed squamous cell carcinoma as noted before.