In this study, we synthesized novel trimetallic catalyst, PdPtAu, and characterized it electrochemical activity toward formic acid. The PdPtAu was prepared with NaBH4 as a reducer and calcinated at 95°C. Once it was synthesized, its crystalline structure and the extent of average particle size were investigated by X-ray diffraction and transmission electron microscopy. For this work, we investigated electrochemical activity of homemade PdPtAu toward formic acid, and compare it with those of commercial Pd, Pt and Au nanoparticles via cyclic voltammetry (CV) and chronoamperometry (CA) studies. To investigate the stability of our novel catalyst for formic acid oxidation and compare it with commercial noble nanoparticles, we measured their currents as a function of time over 2 hours in 5 M HCOOH + 0.5 M H2SO4, while a constant voltage was applied on the working electrodes. Additionally the electrodes were stripped after they were operated for 2 hours in 5 M HCOOH to understand the effects of surface poisoning on different catalysts. From this work, we conclude that our novel catalyst, PtPdAu, has a higher stability than the Pd and a higher electrochemical activity than Pt in the formic acid. Moreover, we observed that the PdPtAu is resistant to non COads species comparing to the Pd.