Diamond growth on Ti6Al4V substrate has been studied using a hot filament assisted technique. The substrate surface pretreatment consisted of polishing with 1-mu m diamond paste using oxalic acid followed by pitting in an ultrasonic bath with a 0.25-mu m diamond powder suspension in n-hexane for 20 min. The main parameters of the diamond growth with CH4/H-2 gas mixture and the mechanical properties of the substrate have been studied as a dependence of substrate temperature. The film was completely formed after 20 min at a 800 degrees C substrate temperature. The adherence between film and substrate has been shown to be strongly dependent on substrate temperature and growth time. Adherent and good quality CVD diamond films, as thick as 10 mu m, have been obtained at a 600 degrees C growth temperature. Stress dependence on growth parameters has been studied by Raman spectroscopy.