Patient-derived xenograft (PDX) models for cancer research have recently attracted considerable attention in both the academy and industry (Hidalgo et al., 2014; Wilding and Bodmer, 2014). PDX models have been developed from different tumor types including lung cancer to improve the drug development process. These models are used for pre-clinical drug evaluation and can be used for the predictive results of clinical outcomes because they conserve original tumor characteristics such as heterogeneity, complexity and molecular diversity (Kopetz et al., 2012). Additionally, PDX model provides the potential tool for the personalized drug therapy. In this protocol, we present methods for the establishment of PDX in mice using primary tumor tissues from patients with small cell lung cancer (SCLC).