The main reason for unfavourable surgical outcome of lung cancer is latent distant metastases over looked during surgery, which ultimately cause recurrence, or death of the patients even in cases undergoing curative surgery. This fact necessitates the indispensable use of systemic adjuvant therapy in patients under going surgery for lung cancer. There have been mary reports concerning the clinical efficacy of surgical adjuvant chemotherapy for non-small cell lung cancer using various kinds of drugs in various treatment modalities, but the results have been controversial. During the past eleven years, we have used postoperative chemotherapy in three ways over three different periods: in the earliest period, short-term combined chemotherapy (STCC) was used, in the middle period, intermittent long-term combined chemotherapy (ILTCC) was used in combination with immunotherapy for a randomized group, and in the latest period, when continuous long-term combined chemotherapy (CLTCC) with immunotherapy was employed. A comparison was then made between these three kinds of treatment groups. In Comparing of the results obtained for the earliest and middle periods, ILTCC showed a significantly improved beneficial effect over STCC in terms of further increased survival rate. Furthermore, by randomized study, it was clarified that the favourable effect of ILTCC was further improved by concomitant use of immunotherapy. CLTCC with immunotherapy carried out in the latest period seemed to be prevent early recurrences in patients with stage I or II who underwent curative surgery, even though a short-term observation period of for 20 months was employed. It is conceivable that the latest treatment modality used will exerted best the most favourable beneficial effect in comparison with the two early treatments. A review of the literature was presented along with a discussion of the clinical value of chemotherapy and immunochemotherapy as a surgical adjuvant.