Objectives: The primary objective of this study was to compare the occurrence of acute kidney injury (AKI) in patients with cystic fibrosis (CF) receiving intravenous (IV) vancomycin monitored through single serum trough concentrations and twopoint estimated area under the curve (AUC). Time to next exacerbation and return to baseline lung function were also assessed.Methods: A retrospective review was conducted in patients of all ages with CF admitted to the University of Kentucky who received IV vancomycin between October 2015 and January 2021. Patients were excluded if they received less than 5 days of IV vancomycin therapy.Results: A total of 113 adults and 42 pediatric encounters met the inclusion criteria.There was no statistically significant difference in occurrence of AKI, however, all grade 2-3 AKIs were in the serum through the monitoring group. Adult patients monitored with AUC also had a higher return to baseline lung function over trough monitoring (86% vs. 57%) (p = 0.002). There was not a statistically significant difference in time to the next exacerbation in either group.Conclusions: Adult patients with CF experienced less severe AKIs when monitored with AUC versus trough. The results of this study indicate that AUC monitoring may enhance the efficacy of IV vancomycin in adult patients with CF.