Vancomycin is widely prescribed to treat infections caused by methicillin‑resistant Staphylococcus aureus (MRSA). According to the Infectious Disease Society of America 2011 MRSA guidelines for adults, trough concentrations of 15–20 µg/ml were recommended with vancomycin 15–20 mg/kg/dose every 8–12 h not to exceed 2 g per dose in patients with normal renal function. As the data for dosage and monitoring of vancomycin in children are still controversial, physicians often follow the guidelines established for adults. To evaluate serum vancomycin trough concentrations in pediatric patients with currently recommended dosing regimen, we evaluated clinical data. Methods: This retrospective observational study collected pediatric patients aged <18 years for whom vancomycin was administered at a single medical center between 2009 and 2015. Results: Fifty pediatric patients were analyzed. Two groups were identified according to the vancomycin dosage. Fourteen (28%) patients underwent vancomycin at 60 mg/kg/day (high dose) and 36 (72%) patients at 40 mg/kg/day (low dose). The average serum vancomycin trough concentrations of the two groups were 13.12 µg/ml (high‑dose group) and 9.02 µg/ml (low dose group), respectively. In addition, 71% (high‑dose group) and 91% (low‑dose group) of patients could not reach the target trough concentrations 15–20 µg/ml, set by the Infectious Disease Society of America. Conclusion: This investigation revealed that the current recommended vancomycin dosing regimens in children (40–60 mg/kg/day) mostly brought out trough concentrations <10 µg/ml in this research population.