Background: Community-acquired pneumonia (CAP) is a serious and common infectious disease with a high rate of morbidity and mortality among adults. Appropriate antibiotic treatment is therefore vital for reducing the disease incidence. Objective: This study aimed at determining the trends in antibiotic use in hospitalized patients with CAP. Methods: A retrospective study involving 479 medical records of hospitalized adults with CAP was undertaken at Tien Giang Central General Hospital in southern Vietnam during 2018–2019. Collected data included patient socio-demographic characteristics and administered antibiotic therapy. Results: Of the 479 CAP cases, 53.8% were female and more than half were aged 65 and above (average age 66.4±18.3 years). Cardiovascular diseases, gastrointestinal disorders, and pulmonary diseases were the most common morbidity of patients with CAP. Overall, 43% of the patients had used antibiotics before hospital admission. In the initial treatment, the most frequent single prescribed antibiotics were amoxicillin/clavulanic acid, ceftriaxone, and levofloxacin. Double combinations of the antibiotics in the initial treatment were used in 75.8% of the cases. Overall, 78.6% of the patients had good responses to the first-choice antibiotics. A negative association was noted between the pneumonia severity and antibiotic effectiveness (P<0.05). Conclusions: Although the initial treatment was successful in the majority of hospitalized patients with CAP, the severity of pneumonia still required attention from healthcare professionals to improve the effectiveness of the treatment.