Flavonoids, a diverse group of natural compounds abundant in plants, fruits, and seeds, are not only responsible for the vibrant colors, fragrances, and flavors found in nature but also possess significant health benefits. Representing a secondary metabolite, these phytonutrients contribute to overall well-being. They have garnered considerable interest due to their diverse biological roles, encompassing antioxidant, anti-inflammatory, and anticancer properties. Flavonoids exert anticancer properties by interfering with different signaling pathways and molecules. Also, they have been demonstrated to exert chemosensitization features, where flavonoids may enhance the effectiveness of chemotherapy, and hold promise for improving cancer treatment outcomes as they have been discovered to make cancer cells more responsive to treatment. Understanding their influence on the regulation of cellular signaling provides a foundation for exploring their potential in combination with different chemotherapy agents and their possible single use for cancer treatment. Besides, they are believed to present a cost-effective approach to cancer therapeutics with possible implications for reducing the side effects of the current chemotherapy regimens, which can be a great therapeutic strategy for treating cancer types, including leukemia. This chapter explores potential approaches for creating anticancer treatments, focusing on leukemia, through integrating flavonoid nutraceuticals with traditional chemotherapy agents.