Interest in quinoa as a functional food ingredient is currently emerging. The flours from white, red and black quinoa seeds were analysed in terms of total polyphenol content and antioxidant activity. They were incorporated at 25% on flour basis into the bread dough formula to evaluate their potential to improve the functional properties of wheat breads. The contribution of extractable polyphenols (soluble forms) and the largely unexplored hydrolysable polyphenols (bound forms that can be found intheresiduesoftheformer)weretakenintoaccounttoreflectarealistichealth-promotingpotentialofbreads.Theredandblack quinoa varieties stood out compared to wheat flour, with about double the polyphenol content and up to 4.7-fold increments in antioxidant activity when considering the sum of extractable and hydrolysable polyphenols. The red and black flours were equally effective in intensifying the antioxidant properties of bread despite the baking process (between 2- and 3-fold). They producedsignificantchangesintheparametersthatdescribecrustandcrumbcolour(L*,a*,b*).Acleardarkeningwasobserved comparedtothecontrolbread,anappealingattributeforloversofunconventionalandnaturalproducts.Accordingtoourresults, the flours from the coloured quinoa seeds could be considered interesting antioxidant sources and be applied as natural ingredientsinbread-making;new,promisingandvaluableunconventionalproductsforconsumersandproducerscouldbedeveloped.