There is a need of antibacterial prosthetic devices that can offer long-term protection against infection after implantation. In the present study, a chemical synthesis method is used for the synthesis of silver nanoparticles (Ag NPs) on anodized Ti6Al4V (a Ti alloy with 6 % wt. Al and 4 % wt. V). The reported method for Ag NPs deposition is easy, rapid and provides an optimal coating not only on the surface of TiO2 nanotubes but also inside them, which favors a continued Ag+ release. In contrast to the bibliography, where Ag+ is released within the first 14 days, we report a sustained release until 46 days in simulated body fluid (SBF) which will be helpful to obtain long-term antibacterial prosthetic devices. Anodization charge has been proven to be a key parameter; an 80 C anodizing charge produced materials with higher and more sustained Ag+ release than the 10 C anodizing charge (5,58 mg/L vs. 3,19 mg/L after 46 d, respectively). Electron microscopy characterization showed a uniform distribution of Ag NPs on the surface of both anodic layers. In the case of the 80 C charge, Ag NPs were also located inside the TiO2 nanotubes as observed in the cross-section analysis of the anodic layer. A higher amount of Ag NPs was deposited on the 80 C anodized sample due to a higher surface area and thicker anodic layer (110 nm vs. 80 nm) where NPs could be fixed (as analyzed by Energy Dispersive X-ray) (2,87-fold higher than 10 C anodized sample). The 80 C anodizing charge also produced more bioactive surfaces since the growth of apatite on its surface in SBF was observed, but not in the case of 10 C anodizing charge. The 80 C anodized Ti6Al4V + Ag NPs showed excellent results for antibacterial activity and biofilm formation reduction when tested against Staphylococcus aureus V329 and Staphylococcus epidermidis RP62A strains. A lethality of 99,9 % for both strains was obtained when compared to the Ti6Al4V anodized samples without Ag NPs.