The crystallisation behaviour of syndiotactic poly(propene-co-octene) (P-co-O)-X with octene contents, X, of 4, 15, 20, 40, and 67 wt% is studied by light microscopy, atomic force microscopy (AFM), small angle X-ray scattering (SAXS), wide angle X-ray scattering (WAXS) and differential scanning calorimetry (d.s.c.) The decrease of equilibrium melting points with increasing octene content is in agreement with theoretical values obtained from the copolymer melting equation of Flory. WAXS measurements show that (P-co-O)-4 forms at relatively low supercoolings the type III unit cell known from s-PP homopolymer. For higher supercoolings and for higher octene contents WAXS traces typical for the type II unit cell are observed exclusively. AFM and light microscopical investigations show that the crystalline morphology depends strongly on the octene content. Similar to s-PP homopolymer, (P-co-O)-4 isothermally crystallised at T-c = 132 degrees C forms single-crystal-like entities and bundle-like morphologies. An important difference to s-PP homopolymer is the absence of cracks and ripples in the single-crystal-like entities, that are typical for s-PP homopolymer. In contrast to s-PP, (P-co-O)-15 forms spherulites at higher crystallisation temperatures and a granular morphology at lower crystallisation temperatures. A similar granular morphology in the nanometer range is also found for (P-co-O)-40. SAXS measurements show that (P-co-O)-15 isothermally crystallised at 90 degrees C forms lamellae with a thickness of approximately 3.5 nm. In the SAXS trace of (P-co-O)-40 a long period cannot be observed. The large scattering at small scattering vectors can be related to the granular morphology.