Neutrophils, the most abundant white blood cells, play a dual role in cancer: some promote tumor growth while others inhibit it. Recent research has identified two main types of tumor-associated neutrophils (TANs): N1, which have anti-tumor properties, and N2, which support tumor growth. Targeting these populations offers new therapeutic strategies for cancer treatment. Neutrophils can be engineered for drug delivery and used to remodel the tumor microenvironment (TME). Their natural ability to respond to inflammation and cross physical barriers makes them effective carriers for delivering drugs and therapeutic agents to tumors. Neutrophils and their derivatives, such as membranes and extracellular vesicles (EVs), are being explored as advanced drug delivery systems due to their stability, targeting ability, and capacity to enhance therapeutic efficacy. Neutrophil-based drug delivery systems, including living cell delivery, membrane-coated nanoparticles, and EVs, are being developed to improve cancer therapy. These systems can deliver chemotherapy, photodynamic/photothermal therapy, and immunotherapy agents to tumors with high specificity and efficiency. Neutrophils can also be used to enhance the immune response against cancer by stimulating T cell activation and IFN-γ release. The dual role of neutrophils in cancer highlights the potential of targeting them for improved cancer treatment outcomes.Neutrophils, the most abundant white blood cells, play a dual role in cancer: some promote tumor growth while others inhibit it. Recent research has identified two main types of tumor-associated neutrophils (TANs): N1, which have anti-tumor properties, and N2, which support tumor growth. Targeting these populations offers new therapeutic strategies for cancer treatment. Neutrophils can be engineered for drug delivery and used to remodel the tumor microenvironment (TME). Their natural ability to respond to inflammation and cross physical barriers makes them effective carriers for delivering drugs and therapeutic agents to tumors. Neutrophils and their derivatives, such as membranes and extracellular vesicles (EVs), are being explored as advanced drug delivery systems due to their stability, targeting ability, and capacity to enhance therapeutic efficacy. Neutrophil-based drug delivery systems, including living cell delivery, membrane-coated nanoparticles, and EVs, are being developed to improve cancer therapy. These systems can deliver chemotherapy, photodynamic/photothermal therapy, and immunotherapy agents to tumors with high specificity and efficiency. Neutrophils can also be used to enhance the immune response against cancer by stimulating T cell activation and IFN-γ release. The dual role of neutrophils in cancer highlights the potential of targeting them for improved cancer treatment outcomes.