We herein report an eco-friendly synthesis of platinum nanoparticles (Pt-NPs) using aqueous extracts from water hyacinth plant as efficient reducing and stabilizing agents. The colour change and optical analysis confirmed the formation of Pt-NPs. Transmission electron microscope (TEM) analysis showed that the as-synthesised Pt-NPs are small and spherical in shape with average diameter of 3.74nm while dynamic light scattering (DLS) analysis showed hydrodynamic size and zeta potential of 73.3nm and −0.0536mV respectively. Fourier transform infrared spectroscopy (FTIR) indicated that, the presence of hydroxyl, nitrogen and carbohydrate groups present in the extract are responsible for the reduction and capping of Pt-NPs.