Platinum nanoparticles (PtNPs) offer significant promise in cancer therapy by enhancing the therapeutic effects of platinum-based chemotherapies like cisplatin. These nanoparticles improve tumor targeting, reduce off-target effects, and help overcome drug resistance. PtNPs exert their anti-cancer effects primarily through the generation of reactive oxygen species (ROS), which induce oxidative stress and apoptosis in cancer cells. Additionally, PtNPs interact with cellular signaling pathways such as PI3K/AKT and MAPK, sensitizing cancer cells to chemotherapy. Advances in PtNP synthesis focus on optimizing size, shape, and surface modifications to enhance biocompatibility and targeting. Functionalization with biomolecules allows selective tumor delivery, while smart release systems enable controlled drug release. In vivo studies have shown that PtNPs significantly inhibit tumor growth and metastasis. Ongoing clinical trials are evaluating their safety and efficacy. This review explores PtNPs' mechanisms of action, nanotechnology advancements, and challenges in biocompatibility, with a focus on their potential integration into cancer treatments.