<p>Vancomycin is a commonly used antibiotic, which requires therapeutic drug monitoring to ensure optimal treatment. Microsampling assays are attractive tools for pediatric clinical research and therapeutic drug monitoring. A LC-MS/MS&nbsp;method for the quantification of vancomycin in human whole blood employing volumetric absorptive microsampling (VAMS) devices (20&nbsp;μl) was developed and validated. Vancomycin was stable in human whole blood VAMS under assay conditions. Stability for vancomycin was established for at least 160&nbsp;days as dried microsamples at -78°C. This method is currently being utilized for the quantitation of vancomycin in whole blood VAMS for an ongoing pediatric clinical study and representative clinical data are reported.</p>