The Fused Deposition Modelling (FDM) has become one of the most used techniques to 3D object rapid prototyping. In this process, the model is built as a layer-by-layer deposition of a feedstock wire. In recent years, the FDM evolved from rapid prototyping technique towards a rapid manufacturing method, changing the main purpose in producing finished components ready for use. Thus, the prediction of the mechanical properties of this new technology has an increasingly important role. Previous papers have highlighted the orthotropic mechanical behaviour of FDM parts showing that the stacking sequence controls the mechanical properties of FDM parts. The aim of this work is to describe the mechanical behaviour of FDM parts by the classical laminate theory (CLT). In order to reach this objective, the values of the elastic modulus in the longitudinal and transverse directions to the fibre (E1, E2), the Poisson's modulus (ν12) and the shear modulus (G12) will be experimentally measured. Display omitted •Fused deposition modelling parts show an orthotropic behaviour.•The mechanical properties of the layer decrease with the raster angle increasing.•Classical laminate theory well predicts the elastic behaviour for both PLA and ABS.