The article discusses the growing threat of multidrug-resistant (MDR) *Acinetobacter baumannii* in hospitals, emphasizing its increasing prevalence and the challenges it poses for healthcare systems. *A. baumannii* is a significant nosocomial pathogen, causing a range of infections, including pneumonia and bloodstream infections, among critically ill patients in intensive care units (ICUs). The article highlights the complex taxonomic history of the genus *Acinetobacter*, with 17 named species and 15 genomic species identified through DNA–DNA hybridization. *A. baumannii* is particularly concerning due to its resistance to multiple antimicrobial agents, including carbapenems, polymyxins, and tigecycline, making it fully refractory to many available treatments. The article reviews the epidemiology, antimicrobial resistance, and clinical impact of *A. baumannii* infections. It discusses the identification methods for *Acinetobacter* species, the role of genotypic methods like amplified fragment length polymorphism (AFLP) and DNA sequence analysis in species identification. The clinical manifestations of *A. baumannii* infections, such as ventilator-associated pneumonia and bloodstream infections, are described, along with risk factors for acquisition and infection. The article also explores the mechanisms of antimicrobial resistance in *A. baumannii*, including the use of chromosomal resistance genes and horizontal gene transfer. It emphasizes the need for infection control measures to prevent the spread of MDR *A. baumannii*, such as strict isolation protocols and environmental surveillance. Treatment options for *A. baumannii* infections are discussed, with a focus on the limited efficacy of broad-spectrum penicillins, cephalosporins, and fluoroquinolones. The use of sulbactam, polymyxins, and tigecycline is highlighted as potential treatments, although their effectiveness is limited by resistance. Finally, the article calls for further research into the mechanisms of *A. baumannii* resistance and its adaptability in hospital environments. It underscores the need for new antibiotics and host-defence peptides to combat the growing threat of MDR *A. baumannii*.The article discusses the growing threat of multidrug-resistant (MDR) *Acinetobacter baumannii* in hospitals, emphasizing its increasing prevalence and the challenges it poses for healthcare systems. *A. baumannii* is a significant nosocomial pathogen, causing a range of infections, including pneumonia and bloodstream infections, among critically ill patients in intensive care units (ICUs). The article highlights the complex taxonomic history of the genus *Acinetobacter*, with 17 named species and 15 genomic species identified through DNA–DNA hybridization. *A. baumannii* is particularly concerning due to its resistance to multiple antimicrobial agents, including carbapenems, polymyxins, and tigecycline, making it fully refractory to many available treatments. The article reviews the epidemiology, antimicrobial resistance, and clinical impact of *A. baumannii* infections. It discusses the identification methods for *Acinetobacter* species, the role of genotypic methods like amplified fragment length polymorphism (AFLP) and DNA sequence analysis in species identification. The clinical manifestations of *A. baumannii* infections, such as ventilator-associated pneumonia and bloodstream infections, are described, along with risk factors for acquisition and infection. The article also explores the mechanisms of antimicrobial resistance in *A. baumannii*, including the use of chromosomal resistance genes and horizontal gene transfer. It emphasizes the need for infection control measures to prevent the spread of MDR *A. baumannii*, such as strict isolation protocols and environmental surveillance. Treatment options for *A. baumannii* infections are discussed, with a focus on the limited efficacy of broad-spectrum penicillins, cephalosporins, and fluoroquinolones. The use of sulbactam, polymyxins, and tigecycline is highlighted as potential treatments, although their effectiveness is limited by resistance. Finally, the article calls for further research into the mechanisms of *A. baumannii* resistance and its adaptability in hospital environments. It underscores the need for new antibiotics and host-defence peptides to combat the growing threat of MDR *A. baumannii*.