This paper proposes a fully coupled multi-scale finite element model for the mechanical description of a new composite material inspired in wood cell-walls. The constitutive response of the composite is described by means of a representative volume element (RVE) in which the fibre is represented as a periodic alternation of rigid and soft portions of material. Furthermore, at a lower scale the overall constitutive behavior of the fibre is modelled as a single material defined by a second RVE. Numerical tests demonstrate substantial gains in terms of resistance to failure, toughness and in the control of the overall flexibility/stiffness balance in the material. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11