Ti6Al4V is widely used in biomedical implants due to its corrosion resistance and biocompatibility. However, it suffers from poor tribological performance and early failures. To enhance its surface properties, Diamond-like carbon (DLC) coatings are applied and, when deposited by plasma-assisted chemical vapour deposition (PA-CVD), the addition of different gas precursors might improve their properties. In this study, four DLC coatings (a-C:H, a-C:H:Si, a-C:H:N, and a-C:H deposited with supplemental H 2 gas) were deposited onto Ti6Al4V using PA-CVD. Their structure, thickness, mechanical properties and adhesion were characterized. Tribological behaviour was evaluated by Pin-On-Disk tests using an alumina ball under dry conditions or submerged in either 5 % NaCl or Ringer's solution. Friction coefficients were measured, and wear tracks were analysed using optical, confocal and electron microscopy. Additionally, time-to-failure tests were conducted under Ringer's solution until coating failure. The silicon-doped DLC exhibited the highest mechanical properties, thickness and adhesion. Nevertheless, it showed the highest wear volume under dry conditions, 8 × 10 −6 mm 3 N −1 m −1, likely due to the formation of hard and abrasive particles. For the other coatings, wear rates were two orders of magnitude lower, around 9 × 10 −8 mm 3 N −1 m −1 in dry conditions. In submerged tests, the Si-doped DLC failed early, whereas the a-C:H deposited with supplemental H 2 gas demonstrated the best wear resistance at 1 × 10 −7 mm 3 N −1 m −1 and a friction coefficient of about 0.08. In time-to-failure tests, nitrogen-doped coating displayed an outstanding resistance, breaking after 420,000 cycles, likely due to higher residual compressive stresses.