The behavior of different aging chestnut treatments (chips, barrels, toasting process, and aging time) on the phenolic profile and color characteristics of Tempranillo red wines has been evaluated. Chestnut treatment produced a considerable decrease of anthocyanic phenolic compounds and an increase of benzoic acids in aged wines. In contrast, the effect of toasting process was not very significant on the phenolic composition of aged wines. Meanwhile the effect of time was a crucial parameter regarding the pyranoanthocyanin and flavonol content, attributable not only to the slow evolution and transformation of wine phenolic compounds, but also to the micro oxygenation process suffered through the pores of barrels over the aging time. Results also strongly suggested that with the use of chestnut chips a considerable sorption effect of free flavanols was observed. All these modifications were reflected on the chromatic characteristics of aged wines.