This study aims to evaluate the hygroscopicity and thermochemical properties of pine wood/polymer composites prepared by in situ polymerisation of methyl methacrylate (MMA) using glycidyl methacrylate (GMA) and methacrylic acid (MAA) as cross-linkers. The pine wood samples were impregnated in a vacuum/pressure system and polymerised in an oven at 90 degrees C for 10 h, using benzoyl peroxide at 1.5 wt.% as catalyst. The composite was characterised through dynamic wettability, water uptake and dimensional stability tests, ATR-IR spectroscopy, TGA, and DSC. ATR-IR spectra show an increase of the peaks at 1746, 1460, and 1145 cm(-1) corresponding to the chemical structures of the polymers into the pores and capillaries of treated wood. The TGA and DSC analysis pointed out a chemical interaction between the copolymer and the wood cell wall in composites with GMA and MM. The composites prepared with MMA presented improvements for the hygroscopicity and dimensional stability properties by 50%. However, the addition of GIVIA and MM resulted in the best increases for hydrophobicity and dimensional stability of the samples, similar to 65-78%. 2014 Elsevier B.V. All rights reserved.