The platinum-catalysed hydroxycarbonylation of olefins is reported for the first time. Using a combination of PtCl₂/2,2′-bis(tert-butyl(pyridin-2-yl)phosphanyl)-1,1′-binaphthalene (Neolephos) in the presence of sulfuric acid [0.6 M] in acetic acid selective carbonylation of terminal aliphatic olefins proceeds to good yields and selectivities to the corresponding carboxylic acids. Comparing the reactivity of different butenes (iso- and n-butenes), the terminal olefin can be selectively carbonylated.