BACKGROUND: Acute otitis media (AOM) is a leading cause of healthcare visits, antibiotic prescription and complications in children aged under 5 years. Following the introduction of pneumococcal conjugate vaccines (PCVs), non-typeable OBJECTIVES: To determine the frequency and characteristics of the pathogens related to AOM in Vietnam in children ≤5 years old. METHODS: This was a cross-sectional study performed at the Vietnam National Children's Hospital from October 2021 to December 2023 in children ≤5 years old diagnosed with acute suppurative otitis media. Clinical features of the children were described. Pathogens of interest were identified by culture or real-time PCR (rtPCR). The antibiotic susceptibility profiles of RESULTS: In total, 482 children ≤5 years old were included, of which 70.8% were ≤2 years old and 61% had an history of AOM. The most frequent bacteria isolated were CONCLUSIONS: The pathogens most frequently associated with AOM in this study were in line with previous findings. Many isolates were resistant to commonly given oral antibiotics. These results can inform decision-making on AOM prevention and treatment strategies in Vietnam.