The prognosis of patients with multilevel mediastinal lymph node metastasis remains poor notwithstanding the progress in multimodal therapy in non-small cell lung cancer. We conducted a feasible study of intermittent adjuvant chemo-immunotherapy after surgery for patients with multilevel mediastinal lymph node metastasis of non-small cell lung cancer. Eleven patients with pathologically N2 or N3 lung cancer (10, adenocarcinomas; 1, squamous cell carcinoma) were enrolled. Five completely resected cases received systemic chemo-immunotherapy and six incompletely resected cases received local chemo-immunotherapy by an indwelling catheter in the thoracic cavity. Cisplatin-based and dose-dependent anti-cancer drugs were selected on the basis of sensitivity tests. Either adoptive immunotherapy with interleukin-2 and lymphokine-activated killer cell or combination of interferon gamma# and OK432 were administered after chemotherapy. This adjuvant therapy was performed every 2-3 months after surgery for 2 years. The 2-year survival rate for all cases were 72.7% and the 2-year disease-free survival were 36.4%. The 2-year survival rate for five completely resected cases and six incompletely resected cases was 80% and 66.7%, respectively. Combined intermittent chemo-immunotherapy after surgical resection of tumors may be a promising modality to improve the survival of patients with multilevel mediastinal lymph node metastasis in non-small cell lung cancer.