A study was conducted on four commercial Waxy Oil green cokes with varying catalyst (Fe3O4) concentrations (ash content: 1.84-11.18%), to determine the effect thereof on the structural characteristics of calcined (1400 degrees C) and pre-graphitised (2000 degrees C) cokes. An increase in the catalyst content of the coke shows a substantial detrimental effect on the overall anisotropy of the carbon microtexture. Catalyst particles below 100 mu m) were found to present a physical barrier around which the anisotropic flow domains formed. At higher catalyst concentrations the catalyst dominates the carbon microtexture; however, there is still evidence of flow patterns albeit with a shorter range. XRD powder data and Raman spectroscopy provide evidence of multiphase graphitisation in both the calcined coke and pre-graphite. The crystal development of the calcined coke is dominated by catalytic graphitisation and that of the pre-graphite showed a greater dependence on thermal graphitisation. This is the first scientific study of the effect of catalyst concentration on the characteristics of this novel coke and proves the disingenuous comparability thereof with a highly anisotropic coke (e.g. needle coke). (C) 2011 Elsevier Ltd. All rights reserved.