Abstract This study presents an Ilex paraguariensis leaf infusion with important potential as natural iron-chelating. The impact of infusion time and the water volume to obtain an Ilex paraguariensis leaf infusion with high phenolic content and iron chelating activity, such as the stability of these proprieties in the storage time and temperature (immediately and after 24 h at 8 and 25 (C) were assessed. The acute consumption effect of this infusion to reduce iron absorption in vivo was also evaluated. A preliminary crossover trial with volunteers that ingested a meal containing non-haem iron (11.4 mg) with the treatments: Ilex paraguariensis leaf infusion with the highest phenolic content and iron chelating activity (200 mL) or control (200 mL water). Blood samples were withdrawn before and 1, 2, 3 and 4 h after the meal for serum iron measurement. The highest phenolic content (18.1 mg/mL) and iron chelating activity ((100%) were observed for 10 min infusion time using 30 g leaves/300 mL water. Storage at 8 or 25 (C for 24 h decreased total phenolics and di-caffeoylquinic acids by 23.5% and 25.5%, respectively (p< 0.05), without affecting the iron-chelating activity due to a saturating chelating effect at 3.34 mg/mL phenolic content. Inhibition of the iron absorption in vivo by infusion was 78% considering the iron recovery at peak maximum. The in vitro and preliminary in vivo results showed a functional property of the Ilex paraguariensis leaf infusion that may be useful for adjuvant management of iron overload diseases.