Cancer cells exhibit redox imbalance compared to normal cells due to increased metabolic rate, mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This imbalance can regulate gene expression, alter protein stability, and modulate cellular programs, making cancer treatment challenging. Nanotechnology offers new opportunities to modulate redox states in cancer cells due to their excellent designability and reactivity. Various nanomaterials are being researched to enhance reactive oxygen species (ROS) production, disrupt endogenous antioxidant defense systems, or both. The review describes the physiological features of redox imbalance in cancer cells, challenges in modulating redox states, and nanomaterials that regulate redox imbalance. It also proposes future perspectives in this field, aiming to provide guidance for designing nanomaterials-based approaches for cancer therapy, particularly for cancers resistant to radiotherapy or chemotherapy.Cancer cells exhibit redox imbalance compared to normal cells due to increased metabolic rate, mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This imbalance can regulate gene expression, alter protein stability, and modulate cellular programs, making cancer treatment challenging. Nanotechnology offers new opportunities to modulate redox states in cancer cells due to their excellent designability and reactivity. Various nanomaterials are being researched to enhance reactive oxygen species (ROS) production, disrupt endogenous antioxidant defense systems, or both. The review describes the physiological features of redox imbalance in cancer cells, challenges in modulating redox states, and nanomaterials that regulate redox imbalance. It also proposes future perspectives in this field, aiming to provide guidance for designing nanomaterials-based approaches for cancer therapy, particularly for cancers resistant to radiotherapy or chemotherapy.