Abstract: OBJECTIVE To analyze the distribution of pathogenic bacteria and their antibacterial drug resistance in culture-positive bronchoalveolar lavage fluid (BALF) specimens, providing a basis for rational clinical use of antibacterial drugs. METHODS A retrospective analysis was conducted on positive bacterial isolates from BALF specimens submitted by the Affiliated Hospital of Yunnan University between Jan. 2020 and Dec. 2023. RESULTS Among 5 817 BALF specimens tested, 1 577 strains of pathogenic bacteria were isolated. The top five pathogenic bacteria were: Pseudomonas aeruginosa (19.66%), Klebsiella pneumoniae (18.90%), Acinetobacter baumannii (15.03%), Candida albicans (6.98%) and Staphylococcus aureus (6.28%). Drug susceptibility testing revealed that P. aeruginosa exhibited a resistance rate of approximately 40% to carbapenems but less than 10% to aminoglycosides, and less than 20% to piperacillin/tazobactam and colistin. The drug resistance rates of the A. baumannii to carbapenems showed upward trends year by year. K. pneumoniae showed high resistance rates to carbapenems. The detection rate of methicillin-resistant S. aureus (MRSA) declined annually, and no vancomycin- or linezolid-resistant S. aureus or Streptococcus pneumoniae strains were identified. CONCLUSIONS Gram-negative bacteria in hospital BALF specimens remain the predominant pathogens, with a significant increase in the detection rate of fungi. The situation of bacterial drug resistance is severe, necessitating strengthened etiological surveillance to curb the spread of resistant bacteria.