The cisplatin-based conventional combination chemotherapy has been shown to prolong survival of patients with advanced non-small cell lung cancer (NSCLC), but the treatment effect is only modest and of little clinical significance. Several promising 'new-generation' anti-cancer drugs, such as taxanes, vinorelbine, gemcitabine and irinotecan, have offered both chance and challenge to develop effective chemotherapy against NSCLC. In Japan, large-scale phase III trials of cisplatin-irinotecan combination regimen vs. conventional chemotherapy have been conducted; patient accrual has been completed and the final results will be presented in a couple of years. Other new agents will also be available by the end of 1999, and it will be our important task to evaluate those drugs efficiently. The current standard treatment strategy against unresectable stage III NSCLC is chemo- radiotherapy. However, there remain many questions to be answered through well-designed clinical trials. Those include optimal timing and schedule of the chemoradiotherapy, dose and fractionation of radiation and best chemotherapy regimen. An important randomized trial of concurrent vs. sequential chemoradiotherapy has been conducted in Japan, which has suggested that the concurrent schedule has survival benefit. Many trials of concurrent chemoradiotherapy with the new agents are currently performed or planned, but potential toxicity of the concurrent chemoradiotherapy must be carefully evaluated.