There has been growing concern in worsening survival and renal outcomes following vancomycin-associated nephrotoxicity (VAN) onset, but the factors associated with these phenomena remain unclear. To examine these factors, we performed a retrospective study combining the analysis of two real-world databases. Initially, the FDA Adverse Event Reporting System (FAERS) was used to evaluate the relationship between VAN and mortality using odds ratios (ORs) and 95% confidence intervals (CIs). Next, electronic medical records (EMRs) were examined in a more robust cohort for evaluation of the association between renal outcomes and worsening survival using Cox proportional hazards regression models. FAERS analysis revealed a significant correlation between VAN occurrence and increased mortality (OR: 1.30; 95% CI: 1.17-1.46). EMR analysis showed that non-recovery of VAN was associated with increased hospital mortality (hazard ratio [HR]: 4.05; 95% CI: 2.42-6.77) and one-year mortality (HR: 3.03, 95% CI: 1.98-4.64). The HR for VAN recovery was lower for patients with acute kidney injury (AKI) stage ≥ 2 (HR: 0.09; 95% CI: 0.02-0.40). Thus, worsening survival outcomes were associated with non-recovery of VAN, whereby AKI stage ≥ 2 was a significant risk factor. Progression to severe VAN should be prevented for better survival outcomes.