Yerba mate (YM) is widely consumed in Latin American countries, and its residues can be used as bio‐resources such as reinforced in epoxy composites. The present work aims to produce epoxy resin composites and evaluate the influence of post‐consumed YM as reinforcement. The concentrations of YM used were 5, 10, and 20% (wt/wt). Chemical, thermal, morphological, and dynamic mechanical behaviors were explored. The YM incorporation did not influence chemically on the epoxy structure and a pull‐out phenomenon was observed as YM content increased. The YM at lower concentrations (5 and 10%) led to higher values of activation energies calculated from model‐free isoconversional methods. On the other hand, the composite e/YM 20 wt% improved all dynamic‐mechanical properties. YM proved to be a suitable and cheap reinforcement for epoxy resin.