The electrochemical reactivity of crotyl alcohol (CA) on Pt in acid media has been studied applying electrochemical methods combined with in situ Fourier transform IR spectroscopy (FTIRS) and on-line mass spectrometry (DEMS). Mass spectrometric cyclic voltammograms (MSCVs) and IR spectra, acquired with the alcohol in the solution, point out the formation of CO 2 and crotonaldehyde as oxidation products.On the other hand, spectra recorded during the electroreduction display negative features at 2964, 2934 and 2875cm −1 , which are assigned to the CH 3 and CH 2 asymmetric stretchings and the CH 2 symmetric stretching, respectively. The intensity of these signals confirms that a massive hydrogenation process occurs at E<0.05V RHE with a strong production of hydrocarbons. Accordingly, several reduction compounds (2-butene, butane, propane, propene, ethane and methane) were detected by DEMS.The same products, with the exception of the aldehyde, were established from CA adsorbed species, isolated applying an electrolyte exchange procedure. A feature at 2020cm −1 due to lineal adsorbed CO develops in the IR spectra. These results allow us to propose a general overview of the electrochemical reactions of CA at Pt.