The lattice parameters of 3C-SiC thin films epitaxially grown on 6H-SiC(0001) substrate crystals have been precisely determined by using high resolution x-ray diffraction methods. Reciprocal space maps recorded around symmetrical and asymmetrical x-ray reflections revealed a pseudomorphic growth of the thin film in relation to the substrate lattice, whereas perpendicular to the surface the interplanar spacing of the lattice planes differ slightly Deltad/d = 8.7.10(-4). This implicates inherent thin film strain (epsilon) and stress (sigma) components. The in-plane components are found to be epsilon (11) = -4.8.10(-4) and sigma (11) = 2.26.10(8) N/m(2), whereas perpendicular to the surface the thin film strain component is found to be epsilon (perpendicular to) = 2.8.10(-4).