The ability of certain strains of bacteria to withstand the effects of common antibiotics has led to find novel strategies for the treatment of infections associated to antimicrobial resistance and biofilm development in affected patients. The use of nanoparticles containing antibiotics has demonstrated numerous advantages. As the antibiotic is held into the nanoparticle, chemical composition and modifications on the NP’s surface enable to prolong, localize, target and have a protected drug interaction with the diseased tissue. In this way, higher antibiotic concentrations are attained in the targeted cells, managing to reduce the frequency of the dosages taken, reducing the drug side effects and fluctuation in circulating levels, improving the overall pharmacokinetics. A la rge variety of nanomaterials for efficient antibiotic drug delivery have been developed and their efficacy has been demonstrated. Due to high thermal and chemical stability, high surface area and good biocompatibility, silica nanoparticles are a good option to deliver drugs such as antibiotics. In this chapter, we will give an overview about the use of nanosized silica particles and silica modified nanoparticles loaded with antimicrobial agents for infection prevention and treatment.