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Background and Importance There is a growing interest in intravenous vancomycin therapy supported by therapeutic drug monitoring (TDM). In addition to assaying drug levels, the determination of other clinical laboratory parameters can assist the appropriate interpretation of TDM results.Aim and Objectives Our aim was to review these laboratory parameters and analyse their relevance through case studies of vancomycin monitoring.Materials and Methods We identified and classified the laboratory parameters valuable for clinical decision making in TDM-guided vancomycin therapy. We evaluated the relevant clinical laboratory practice at Semmelweis University, the availability of the assays, and the significance of the identified laboratory parameters with respect to the outcomes of pharmacokinetic modelling and the clinical management of patients.Results The laboratory parameter groups relevant to vancomycin therapy include (A) parameters characterising renal function, (B) additional laboratory parameters required for pharmacokinetic modelling, (C) acute-phase laboratory parameters, (D) parameters indicating acute adverse effects, and (E) microbiological parameters.At Semmelweis University, serum creatinine, urea, albumin, C-reactive protein, procalcitonin, and lactate levels can be requested in addition to vancomycin levels as urgent tests, with differences in their availability to various clinical departments. The minimum inhibitory concentration is determined by broth microdilution in the microbiology laboratory. The case studies presented demonstrate that the relationship between renal function and vancomycin pharmacokinetics can be most effectively characterised by calculating creatinine clearance. The calculated 24-hour area under the concentration–time curve depends strongly on the applied pharmacokinetic model. C-reactive protein concentrations reflected the clinical status reliably, whereas procalcitonin levels were not relevant. Albumin and urea levels were required inputs for a population model incorporated in the TDMx online pharmacokinetic calculator, but their influence on modelling outcomes was negligible.Conclusions and Relevance The measurement of the laboratory parameters identified in this study is essential for conducting clinically meaningful vancomycin TDM, as is the integrated interpretation of pharmacokinetic results and those of the clinical laboratory assays.