Method for impregnating in depth wooden boards, sections or planks with plastic materials, comprising the treatment of the wood, preferably pre-dried and optionally, first under vacuum conditions and then under pressure conditions, with an impregnation solution comprised of the plastic materials in organic solvents during a period of time sufficient to allow the impregnation of the wood with said solution, said impregnation being possibly carried out by osmosis with solutions in organic solvents of said thermoplastic materials and polymerisable thermostable materials, particularly in the case of panels of any type faced with sheets of noble woods by means of urea-formol or phenol-formol.