Acute otitis media (AOM) is a leading cause of antibiotic prescriptions in children worldwide, even in the era of pneumococcal conjugate vaccines. We aimed to assess the bacterial spectrum of AOM in children and to investigate the antimicrobial resistance profile in culture-positive cases. We performed a retrospective, tympanocentesis-based analysis of antimicrobial resistance patterns in children with AOM hospitalized in “St Mary” Emergency Hospital for Children Iasi, Romania, between January 2013 and December 2021. A total of 147 samples have been assessed, 97 (65.98%) of which had positive cultures, with Streptococcus pneumoniae and Haemophilus influenzae as the most common microorganisms. A worrying proportion, 82.85% (58/70), of the Streptococcus pneumoniae strains were multidrug-resistant. The World Health Organization included Streptococcus pneumoniae and Haemophilus influenzae on the medium priority group due to penicillin non-susceptibility and ampicillin-resistant strains, respectively. Consequently, strategies to address the threats of antimicrobial resistance are needed to reduce the potential negative effects on hospitalization costs.