The oxidative dehydrogenation of propane to propene was studied on titanium and vanadium containing zeolites and non zeolitic catalysts, and TS-1 was found to be the most active. In order to investigate the nature of the active site different batches of TS-1 with varying amounts of titanium were examined and characterised with XRD, nitrogen sorption, UV-VIS, ICP-AES, NH3-TPD and pyridine adsorption. Also, the influence of the reaction parameters was investigated. The reaction rate was independent on the oxygen concentration in the feed. With increasing W/F ratios higher conversions could be obtained, but there was a sharp drop in selectivity. The addition of water caused an increase in selectivity, probably due to a competitive adsorption on the active sites. The reaction very likely takes place on the outer surface of the TS-1 crystallites on Lewis acid sites, and a sulfation of the catalyst, which increases the acidity of these sites, resulted in a further increase of the catalytic activity. The maximum conversion obtained was 17% with a selectivity to propene of up to 74%.