Extracellular vesicles (EVs), including exosomes and shed microvesicles (sMVs), play a critical role in cancer progression by facilitating communication between cancer cells and the tumor microenvironment. EVs carry molecules such as oncoproteins, RNA, lipids, and DNA that can alter the phenotype of recipient cells, contributing to cancer development, metastasis, and immune evasion. These vesicles are secreted by various cell types and can be isolated from body fluids, making them promising biomarkers for cancer diagnosis, prognosis, and surveillance. EVs are involved in key cancer hallmarks, including angiogenesis, immune suppression, and epithelial-mesenchymal transition. They also contribute to the formation of pre-metastatic niches, which are essential for cancer cell survival and spread. EVs can transfer oncogenic molecules, such as mutated proteins, fusion gene mRNAs, and oncogenic long non-coding RNAs, to neighboring cells, promoting malignancy. Additionally, EVs can confer drug resistance to cancer cells and influence the tumor microenvironment to support cancer progression. The functional roles of EVs in cancer are increasingly recognized, and their potential as therapeutic targets is being explored. However, challenges remain in standardizing EV isolation, quantification, and analysis, particularly in complex biological samples like blood. Despite these challenges, EVs offer significant potential as diagnostic and therapeutic tools in cancer care.Extracellular vesicles (EVs), including exosomes and shed microvesicles (sMVs), play a critical role in cancer progression by facilitating communication between cancer cells and the tumor microenvironment. EVs carry molecules such as oncoproteins, RNA, lipids, and DNA that can alter the phenotype of recipient cells, contributing to cancer development, metastasis, and immune evasion. These vesicles are secreted by various cell types and can be isolated from body fluids, making them promising biomarkers for cancer diagnosis, prognosis, and surveillance. EVs are involved in key cancer hallmarks, including angiogenesis, immune suppression, and epithelial-mesenchymal transition. They also contribute to the formation of pre-metastatic niches, which are essential for cancer cell survival and spread. EVs can transfer oncogenic molecules, such as mutated proteins, fusion gene mRNAs, and oncogenic long non-coding RNAs, to neighboring cells, promoting malignancy. Additionally, EVs can confer drug resistance to cancer cells and influence the tumor microenvironment to support cancer progression. The functional roles of EVs in cancer are increasingly recognized, and their potential as therapeutic targets is being explored. However, challenges remain in standardizing EV isolation, quantification, and analysis, particularly in complex biological samples like blood. Despite these challenges, EVs offer significant potential as diagnostic and therapeutic tools in cancer care.