This study aimed to explore the metabolic fate of (poly)phenolic compounds in a unique anthocyanin-rich purple barley. Using Balb/c mice, researchers analyzed urine samples after a six-week diet of either standard food or whole-grain barley. They identified 39 (poly)phenolic compounds in the barley and 42 metabolites in urine post-consumption, including unique phase-II conjugates and colonic catabolites. The findings offer insights into the metabolism of these compounds in purple barley, paving the way for future research on its potential health benefits. The dataset includes an experimental summary of the (poly)phenolic profile of a hull-less, purple barley genotype biofortified with anthocyanins, compared to a standard diet. It also covers the (poly)phenolic metabolites identified in urine samples from mice after sustained intake. The barley's (poly)phenolic compounds are categorized into free and bound fractions, including anthocyanins, phenolic acids, flavan-3-ols, and flavones. The metabolites in mice urine predominantly consist of phase-II sulphated, glucuronided, and methylated conjugates, along with colonic catabolites.