Conductive-tip atomic force microscopy (CAFM) was used to explore the effects of high electric fields on silver nanoparticle (NP) arrays embedded inside the pores of mesoporous TiO₂ thin films (MTF). A controlled local modification of the distribution of Ag nanoparticles inside the MTF and their electronic transport properties was carried out. The process is driven by strong electrochemically induced Ag⁺ migration and reduction inside the pores localized around the CAFM tip. Depending on the experimental parameters, we were able to induce drastic and violent changes, both at the surface and at the MTF/Si interface, that is, through the whole scanned region. Therefore, the results reported in this work contribute to the design and development of novel metal NP-based devices at the micro- and nanoscale.