The rise in antibiotic-resistant bacteria has created a pressing need for alternative antibacterial agents. Nanomaterials, with their unique properties, have emerged as promising candidates in this regard. This chapter investigates important aspects of antibacterial nanomaterials from 2017 to 2024. It explores the types of antibacterial nanomaterials, their biocompatibility, and cytotoxicity. Various metal nanoparticles, such as silver (AgNPs) and gold (AuNPs) nanoparticles, have been investigated for their efficacy in medical applications, including biomedical device coatings, drug-delivery systems, and dental treatments. The chapter discusses how different nanomaterials exert their antibacterial effects, the factors influencing their activity, and their potential synergistic effects when combined with traditional antibiotics. The applications of these nanomaterials in combating antibiotic-resistant bacteria and enhancing existing medical treatments are also highlighted.