This review covers the recent developments and the present state of selective oxidation of propane to acrylic acid with molecular oxygen. The current commercial manufacturing process of acrylic acid, as well as the possible oxidation pathways of propane are included as background information. Special attention is given to three classes of leading catalysts: vanadium pyrophosphate, heteropoly acids and salts and mixed metal oxides. Topics covered include the development and the effectiveness of the catalyst systems, the oxidation pathways, and some structural aspects.