Small cell lung cancer (SCLC) is the most aggressive form of lung cancer, characterised by early metastatic dissemination and extremely poor survival rates. The molecular mechanisms intrinsic to SCLC cells that allow them to metastasize are poorly understood. Furthermore, the key immune cell effectors involved in immunosurveillance of metastatic cells remains largely unexplored. In this presentation I will share the progress we have made in identifying the cytotoxic immune cell populations responsible for controlling SCLC dissemination. Moreover, I will describe a novel two-hit SCLC murine model that combines bi-allelic loss of the tumour suppressor genes p53 and Rb1 (hereafter RP mice) with chronic cigarette smoke (CS)-exposure. This model serves as a valuable tool to dissect the contributing effects of CS-exposure on SCLC initiation and progression. Interestingly, we found that CS-exposure potentiates SCLC dissemination in RP mice. Ultimately, a deep understanding of the multifactorial processes underpinning SCLC metastasis will aid in identifying new therapeutic approaches to combat this highly metastatic disease.