<p>Platinum nanoparticles (PtNPs) have emerged as versatile materials with applications spanning catalysis, industry, and biomedicine. Their high surface area, catalytic efficiency, and tunable physicochemical properties enable use in photochemical processes, catalytic converters, biosensing, and therapeutic platforms. In biomedical research, PtNPs exhibit antibacterial, antioxidant, and anticancer activities, making them promising candidates for diagnostics and targeted therapies. This review critically examines recent advances in PtNP synthesis using physical, chemical, and biological approaches, highlighting their respective advantages, limitations, and scalability considerations. Special attention is given to green synthesis strategies employing biological templates as reducing and stabilizing agents. We also summarize characterization techniques and discuss current understanding of PtNP toxicity from in vitro and in vivo studies. Finally, we evaluate biomedical applications, including drug delivery, imaging, and combination cancer therapies, outlining key challenges and research priorities for translating PtNP-based technologies into safe and effective clinical tools. This review critically examines synthesis methods, toxicity concerns, and biomedical applications of PtNPs, highlighting current challenges and opportunities to advance their clinical and industrial utility.</p> Graphical abstract <p></p>