Abstract Purpose The aim of this study was to compare pharmacokinetic characteristics between intermittent infusion and continuous infusion of vancomycin for critically ill patients admitted to intensive care units. Methods Intermittent therapy was administered for 60 minutes and prescribed as a loading dose of 30 mg/kg and continued with 15 mg/kg q12 h. Continuous infusion was prescribed as a loading dose of 30 mg/kg followed by 30 mg/kg on constant infusion pump. Blood samples from vancomycin intermittent infusion group were collected 1 h before third dose, 1 h, 8 h and 24 h after third dose infusion. Blood samples from vancomycin continuous infusion group were collected 1 h after loading dose, 12 h, 24 h, 36 h, and 48 h after continuous infusion initiation. Results Median serum concentration of continuous infusion group at 24-hour was 23.59 µg/mL [14.52-28.97], while of intermittent infusion group at 23-hour was 12.30 µg/mL [7.27-18.12] and on 25-hour was 17.58 µg/mL [12.5-22.5]. Medians AUC24-48h were 357.2 mg.h/L and 530.2 mg.h/L for intermittent infusion and continuous infusion groups, respectively (p = 0.559). Conclusion Vancomycin CI reached steady state earlier, which guaranteed therapeutic levels from the first day and made it possible to manage therapeutic drug monitoring faster.