Background: Small cell lung cancer (SCLC) harbours the most aggressive phenotype of all lung cancers to correlate with its bleak prognosis. The aggression of SCLC is partially attributable to its strong metastatic tendencies. The biological processes facilitating the metastasis in SCLC are still poorly understood and garnering a deeper understanding of these processes may enable the exploration of additional targets against this cancer hallmark in the treatment of SCLC. Recent findings: This narrative review will discuss the proposed molecular mechanisms by which the cancer hallmark of activating invasion and metastasis is featured in SCLC through important steps of the metastatic pathway. The review will discuss SCLC VEGF family expression and vascular mimicry as a means of vasculogenesis, and the role of tumour heterogeneity, DLL3, NFIB, selectin, and B1 integrin in enabling epithelial to mesenchymal transition and subsequent invasion, and the molecular markers expressed by SCLC to assist organ-specific homing during metastasis. The review will also discuss a recent article observing mir-1 mrna upregulation as a potential therapeutic option in targeting the metastatic activity of SCLC. Conclusion: Treatment of SCLC remains a clinical challenge due to its recalcitrant and aggressive nature. Amongst the many hallmarks used by SCLC to enable its aggressive behaviour, that of its ability to invade surrounding tissue and metastasise is particularly notable and understanding the molecular mechanisms in SCLC metastasis can identify therapeutic targets to attenuate SCLC aggression and improve mortality.