Ionic liquids (ILs) are a large group of so-called green solvents with extensive uses in medicine, drug delivery, stabilization of proteins and enzymes, and industrial applications. Active Pharmaceutical Ingredients ionic liquids (API-ILs) are the third generation of ILs. Because of their role precision, biodegradability, and biocompatibility, this class of ILs is gaining interest. This chapter, therefore, aims to recognize the antimicrobial action of non-toxic and biocompatible antibiotics targeting API-ILs that could respond to resistant strains. The World Health Organization (WHO) has published a priority list of pathogens for antibiotic research and development. Among the pathogens are Enterobacteriaceae (Escherichia coli, Klebsiella pneumonia, Serratia spp., Enterobacter spp., Proteus spp., Providencia spp, and Morganella spp), carbapenem-resistant, 3rd generation cephalosporin-resistant, Pseudomonas aeruginosa (carbapenem-resistant), and Acinetobacter baumannii (carbapenem-resistant). The application of API-ILs could assist in overcoming the challenges correlated to the pharmaceutical industry including drug solubility and polymorphism. At present, biocidal characteristic of large cations, such as imidazolium and benzalkonium species are mostly utilized to hinder growth of yeast or bacteria. In this context, this chapter introduces a background on the applications of ILs as antimicrobial agents for microbial resistance. Their corresponding mechanism of ILs and their effect as an antimicrobial agent was investigated, as well. Since the selection of the organic cations and anions in the ILs formulation can tube the biological properties of the ILs, we aim to unveil some of the recent studies that focused on the antimicrobial activities of ILs toward some resistant strains. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021.