In this work we present an extended characterisation of polycrystalline diamond films grown by the acetylene flame chemical vapour deposition (CVD) method. In the first part, scanning electron microscopy (SEM) is used to study the influence of process parameters on diamond crystal morphology. In the second part, various surface analysis techniques are used to study the effects of process parameters on diamond composition and their relation to morphology. Process parameters, such as the substrate temperature and molar ratio between oxygen and acetylene, are seen to have a great influence on the morphology of the films. With an appropriate choice of parameters it is possible to obtain areas of polycrystalline diamond films with good crystallinity acid homogeneous crystal size, which could permit the use of flame CVD as a suitable diamond deposition technique for small area applications.