Phytochemicals have the potential to treat resistant cancer. They are delivered to the target site via nano-based carriers. Promising results are seen in preclinical and in vitro models, as phytochemical-based nanoformulations have improved cell cytotoxicity compared to single agents. They can synergistically inhibit cancer cell growth through p53 apoptosis in MCF-7 breast cancer cell lines. Moreover, synergic viability in reproducible glioma models at half inhibitory concentrations has been shown. Through caspase activation, phytochemical-based nanoformulations also increase cell death in 4T1 breast cancer cell lines. They have shown improved cytotoxicity at half inhibitory concentrations compared to single-agent drugs in cervical cancer. In terms of colorectal cancer, they have the potential to arrest cells in the S phase of the cell cycle and synergistically inhibit cell proliferation. In squamous cell carcinoma of the tongue, they inhibit protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways. This review reports on developments in the therapeutic management of various cancers using phytochemical-based nanoformulations, which have shown potential benefits in the clinical management of cancer patients, halting/slowing the progression of the disease and ameliorating chemotherapy-induced toxicities.