Antibacterials induce a differential risk of acute kidney injury (AKI) in older adults. This study investigated the reporting risk of AKI associated with antibacterials using the individual case safety reports (ICSRs) submitted to the Food and Drug Administration Adverse Event Reporting System (FAERS) database. A case/non-case method was used to assess AKI risk associated with antibacterials between 1 January 2000 and 30 September 2021. Cases were ICSRs for antibacterials with AKI as preferred terms included in the Medical Dictionary of Regulatory Activities (MedDRA) system organ classes 'Renal and urinary disorders' disorders. The analyses were completed on a de-duplicated data set containing only the recent version of the ICSR. Signals were defined by a lower 95% confidence interval (CI) of reporting odds ratio (ROR) ≥ 2, proportional reporting ratio (PRR) ≥ 2, information component (IC) > 0, Empirical Bayes Geometric Mean (EBGM) > 1 and reports ≥4. Sensitivity analyses were conducted a priori to assess the robustness of signals. A total of 3 680 621 reports on ADEs were retrieved from FAERS over the study period, of which 92 194 were antibacterial reports. Gentamicin, sulfamethoxazole, trimethoprim and vancomycin consistently gave strong signals of disproportionality on all four disproportionality measures and across the different sensitivity analyses: gentamicin (ROR=2.95[2.51-3.46]), sulfamethoxazole (ROR=2.97[2.68-3.29]), trimethoprim (ROR=2.81[2.29-3.46]) and vancomycin (ROR=3.35[3.08-3.64]). Signals for gentamicin, sulfamethoxazole, trimethoprim and vancomycin were confirmed by using antibacterials as a comparator, adjusting for drug-related competition bias and event-related competition bias.