The sudden emergence and rapid spreading of viral, bacterial, and fungal infections and the usual development of resistance against traditional molecular drugs prompt the urgent need for alternative approaches to kill or inactivate pathogenic agents. This motivation has inspired a vast number of research works devoted to the design, synthesis, and application of nanomaterials, specifically inorganic plasmonic nanoparticles, as antimicrobial agents. We will pay special attention to articles from 2019 to 2023 where control of the colloidal properties, i.e., size, morphology, and colloidal stability, are properly considered. Here we will discuss the latest advancement in synthesis, colloidal characterization, and antimicrobial activity of Au and Ag nanoparticles, as well as hybrid systems based on combining metallic NPs with inorganic and organic materials. We will also consider contributions focusing on the green synthesis of plasmonic particles, highlighting the opportunities and the need for better control and predictivity of colloidal and functional properties.