Studies on non-small cell lung cancer (NSCLC) patients with KRAS or BRAF mutations are urgently needed to improve clinical outcomes. We evaluated the cytotoxicities of paclitaxel and sorafenib alone and in combination in NSCLC cell lines with KRAS or BRAF mutations and investigated the mechanism of the interaction between the drugs. We found synergistic antitumor efficacy with paclitaxel followed by sorafenib in in vitro and in vivo models of NSCLC. And, we determined that downregulation of the phosphorylated ERK and Rb, and Mcl-1 plays a critical role in the synergistic activity of the drugs. Further clinical trials are needed to verify the antitumor efficacy of this combination.