Updated project metadata. Peptide-Spectrum Match (PSM) Validation with Internal Standards (P-VIS) is an objective approach to validating individual PSMs. A biological sample is analyzed by LC-MS/MS and the data are searched using a traditional approach such as a database search or de novo sequencing. A PSM of interest is identified, and a synthetic version of the putative peptide is obtained. Internal standard peptides (ISPs) are spiked into both the biological sample and the validation peptide sample and both samples are analyzed by LC-MS/MS. Using PSM_validator (https://github.com/Delong-Lab/PSM_validator/releases), an open-source program we created to implement the P-VIS workflow, both the fragmentation spectrum and the chromatographic retention time for the peptide of interest in the biological sample are compared to those of the validation peptide. The same comparisons are made for each of the ISPs, and these results are used to establish a prediction interval for valid matches. If the values for the comparisons between the biological and validation peptide fall within the prediction intervals, the match is considered valid. This submission contains the data and P-VIS results from a study aimed at benchmarking the P-VIS workflow.