Carbon dots are being considered to be novel nanomaterials showing promising antimicrobial applications against bacterial, fungal and viral pathogens. While interacting with microorganisms, they disrupt the cell membrane, induce oxidative stress and interfere with other microbial cellular processes. They also show the synergistic effects when used in combination with antibiotics and antiviral agents. It enhances their efficacy and shows promising results against multidrug resistance. The synergistic effects appear to be promising and novel strategies to disarm the drug-resistant microbes. They hold the potential to combat the broad spectrum of microbes, but on the other hand, toxicity remains a crucial factor for their translation into clinical practice. Although many studies advocate low toxicity of CNDs, concerns regarding their long-term effects and biocompatibility require attention. Therefore, optimisation and modifications of CNDs to minimize the potential harmful effects will ensure their safe applications. Considering their potential, the present chapter aims to discuss the antimicrobial potential of CNDs against microbes, including those that have developed resistance. The chapter further discusses their synergistic effects in combination with antibiotics and antiviral agent, applications in photodynamic therapy and diagnosis, along with their potential harmful effects.