Background: Antibiotic overuse and misuse significantly contribute to antimicrobial resistance (AMR), particularly in developing countries like Bangladesh. Despite national and international efforts to combat this issue, inappropriate antibiotic prescriptions remain common in hospital settings. This study aimed to assess the quality of antibiotic prescriptions and identify the reasons behind irrational antibiotic use at Gonoshasthaya Samaj Vittik Medical College Hospital. Methods: A retrospective cross-sectional study was conducted involving 1007 patients admitted to the Pediatrics, Medicine, Surgery, and Obstetrics & Gynecology departments of Gonoshasthaya Samaj Vittik Medical College Hospital from October 2021 to December 2021. Data were collected through medical record reviews, and antibiotic use was analyzed based on the Standard Treatment Guidelines (STG) for Bangladesh. The rationality of prescriptions was determined by comparing them against the policy-cited choices or microbiological culture and sensitivity results. Results: Antibiotics were prescribed in 90.2% of cases, with 99.5% being administered empirically and only 0.5% based on culture sensitivity tests. Preoperative surgical prophylaxis was the most common reason for antibiotic use (39.3%). Approximately 34.2% of antibiotic use was deemed inappropriate, with incorrect duration being the most frequent cause (32.4%). Antibiotic misuse was highest in the Surgery (61.2%) and Medicine (56.1%) departments, while the Obstetrics & Gynecology department had the lowest misuse rate (1%). Conclusion: Irrational antibiotic use is a major issue in Bangladesh, contributing to growing resistance. Strict adherence to antibiotic guidelines, especially in surgical and medical wards is essential to curb misuse. This study highlights the need for ongoing audits and the development of hospital-specific antibiotic guidelines to combat AMR effectively.