Vanadium pentoxide was supported on calcium, strontium, magnesium and barium hydroxyapatite with a loading of 15 wt% by the wet impregnation technique. The materials were characterized by X-ray diffraction (XRD), ICP-OES, BET, FTIR, scanning electron microscopy, transmission electron microscopy, temperature programmed reduction and temperature programmed desorption. From XRD and infra-red analyses, vanadium was found to exist mainly in the vanadium pentoxide phase with an additional pyrovanadate phase on the surface of the hydroxyapatites. Electron microscopy provides evidence of a homogenous distribution of the vanadium species on the hydroxyapatite. Oxidative dehydrogenation reactions carried out in a continuous flow fixed bed reactor showed that selectivity towards desired products was dependent on the metal in the hydroxyapatite and the phase composition of the oxide. Best selectivity towards heptenes was achieved using the VBa-HAp loaded catalyst. There was a marked decrease in heptenes selectivity and a significant increase in the formation of aromatics with increase in temperature. At a conversion of 16 % at 400 A degrees C, the VBa-HAp showed a selectivity of 51 % towards heptenes, 14 % aromatics (benzene, toluene and phenol) and 15 % oxygenates (2-heptanol and 2-heptanone) for a total value added products selectivity of 80 %. For the other catalysts, a significant observation was the selectivity of 19 % towards C-7 oxygenates obtained using VCa-HAp at a conversion of 16 % at 400 A degrees C. Selectivity towards desired products in the oxidative dehydrogenation of n-heptane over vanadium oxide supported on alkaline earth hydroxyapatites depended on the metal in the hydroxyapatite and the phase composition of the oxide. There was a marked decrease in heptenes selectivity and significant increase in aromatics selectivity with increase in temperature.