This review discusses the role of tumor-derived exosomes (TDEs) in cancer metastasis and drug resistance. TDEs participate in various cancer processes, including tumor microenvironment (TME) remodeling, angiogenesis, invasion, metastasis, and drug resistance. The biogenesis of exosomes involves the formation of multivesicular bodies (MVBs) and their release from cells through endosomal sorting complex required for transport (ESCRT) machinery. TDEs modulate the TME by influencing stemness, angiogenesis, and epithelial-mesenchymal transition (EMT). They promote angiogenesis through the release of angiogenic factors and induce EMT by delivering EMT-inducing molecules. TDEs also enhance migration and invasion by activating signaling pathways and upregulating matrix metalloproteinases (MMPs). Additionally, TDEs contribute to therapy resistance by promoting EMT, activating anti-apoptotic pathways, and altering signal transduction. Exosomes can be engineered to deliver therapeutic agents, such as drugs and functional RNAs, making them potential tools for targeted cancer therapy. Understanding the mechanisms of exosome biogenesis and their roles in cancer progression can inform the development of novel therapeutic strategies to overcome therapy resistance and prevent metastasis.This review discusses the role of tumor-derived exosomes (TDEs) in cancer metastasis and drug resistance. TDEs participate in various cancer processes, including tumor microenvironment (TME) remodeling, angiogenesis, invasion, metastasis, and drug resistance. The biogenesis of exosomes involves the formation of multivesicular bodies (MVBs) and their release from cells through endosomal sorting complex required for transport (ESCRT) machinery. TDEs modulate the TME by influencing stemness, angiogenesis, and epithelial-mesenchymal transition (EMT). They promote angiogenesis through the release of angiogenic factors and induce EMT by delivering EMT-inducing molecules. TDEs also enhance migration and invasion by activating signaling pathways and upregulating matrix metalloproteinases (MMPs). Additionally, TDEs contribute to therapy resistance by promoting EMT, activating anti-apoptotic pathways, and altering signal transduction. Exosomes can be engineered to deliver therapeutic agents, such as drugs and functional RNAs, making them potential tools for targeted cancer therapy. Understanding the mechanisms of exosome biogenesis and their roles in cancer progression can inform the development of novel therapeutic strategies to overcome therapy resistance and prevent metastasis.