This study investigated the effects of different yerba mate (YM) proportions (1.5, 2.5, and 4.5 g YM/100 g whole wheat flour (WWF) and particle sizes (245, 415.5, and 623.9 µm) on dough rheological properties, antioxidant activity, and bread characteristics. The addition of YM leaves led to a possible interaction between its phenolic compounds and the gluten network within the dough, without negative effects on dough formation. However, the larger YM particle size (623.9 µm) caused a weakening of the protein network, resulting in lower quality product compared to the other samples. Improved bread quality was found when the YM leaves were added at 2.5 g YM/100 g WWF. The total amount of phenolic compounds and the antioxidant activity increased as the proportion of YM increased in both flour and bread. Moreover, the phenolic compounds in 2.5 g YM/100 g WWF breads were stable during baking, showing no significant losses in the amount of phenolic compounds and antioxidant activity.These results suggest the YM can be successfully incorporated into baked product, improving its functional characteristics.Practical Application: This study evaluates the technological quality of bakery product made by incorporating yerba mate leaves in whole wheat flour. The results will contribute to the production of a bread with greater functional properties due to the presence of polyphenols and phytochemicals.