The feasibility of the complete systematic nodal dissection by the video-assisted thoracic surgery was prospectively assessed in 22 cases of clinical stage I lung cancer (16 right, 6 left cases). Resection of the designated lobe with the mediastinal lymph node dissection was carried out by the small thoracotomy with the aid of the thoracoscope, followed by the standard surgery to verify the completeness of systematic nodal dissection. Although residual lymph nodes were found in 14 of 22 cases, the residual rate was 2.9% and 2.7% by the number and 2.3% and 2.1% by the weight in right and left cases, respectively. Average time and hemorrhage for performing the procedure were 196 minutes, 216.7 minutes and 157.5 g, 145 g in right and left cases, respectively. As a consequence, sufficient systematic nodal dissection in lung cancer was suggested to be feasible by VATS lobectomy.