Nitrogenated a-C:H films, a-C:H(N), were obtained by plasma decomposition of methane-nitrogen mixtures. The samples were thermally annealed in vacuum for 30 min at fixed temperatures between 300 and 700-degrees-C. Undoped films were implanted at room temperature with 70 keV-N+ at fluences of 6, 10 and 20 x 10(16) N cm-2. The induced structural modifications were studied by Raman spectroscopy through the evolution of the D and G bands. The spectral evolution observed on a-C:H(N) samples shows evidence that a progressive graphitization follows the nitrogen incorporation in these films. Micro-Raman depth profile analysis indicates that the structural and modifications observed on implanted samples are due to the energy deposited by the incident ions. Thermal annealing induces the formation of graphitic domains in a-C:H(N) films.