A method for establishing a posteriori a match between a piece of wood and a log from which the piece of wood has been obtained, comprising the following operating steps: an initial step of taking a wooden log; a scanning step, wherein a tomographic scan of the wooden log is performed; a step of choosing a cutting pattern, during which a cutting pattern for the log is calculated or selected, the cutting pattern comprising information with reference to a subsequent division of the log into pieces of wood; a characterising step, during which for each virtual piece of wood intended to be obtained with the cutting pattern, and starting with the tomographic information available, one or more virtual individualising characteristics are defined which are linked to the distribution and/or size of physical characteristics of the log inside and/or on the surface of the selfsame virtual piece of wood; a saving step, during which those virtual individualising characteristics of each virtual piece of wood are saved in a database, together with information about the identity of the log; a cutting step, during which the log is divided into real pieces of wood according to what is foreseen in the cutting pattern; a selecting step, during which a real piece of wood obtained from the cutting step is selected; an analysing step, during which real information about the distribution and/or size of physical characteristics of the log inside and/or on the surface of the real piece of wood is acquired and, based on that real information, corresponding real individualising characteristics of the real piece of wood are defined; a search step, during which the real individualising characteristics of the real piece of wood are compared with the virtual individualising characteristics saved in the database for virtual pieces of wood, in order to identify a match; and an identifying step, during which an origin of the real piece of wood is identified based on the information about the identity of the log which is saved in the database together with the virtual individualising characteristics of a virtual piece of wood which match the real individualising characteristics of the real piece of wood. an initial step of taking a wooden log; a scanning step, wherein a tomographic scan of the wooden log is performed; a step of choosing a cutting pattern, during which a cutting pattern for the log is calculated or selected, the cutting pattern comprising information with reference to a subsequent division of the log into pieces of wood; a characterising step, during which for each virtual piece of wood intended to be obtained with the cutting pattern, and starting with the tomographic information available, one or more virtual individualising characteristics are defined which are linked to the distribution and/or size of physical characteristics of the log inside and/or on the surface of the selfsame virtual piece of wood; a saving step, during which those virtual individualising characteristics of each virtual piece of wood are saved in a database, together with information about the identity of the log; a cutting step, during which the log is divided into real pieces of wood according to what is foreseen in the cutting pattern; a selecting step, during which a real piece of wood obtained from the cutting step is selected; an analysing step, during which real information about the distribution and/or size of physical characteristics of the log inside and/or on the surface of the real piece of wood is acquired and, based on that real information, corresponding real individualising characteristics of the real piece of wood are defined; a search step, during which the real individualising characteristics of the real piece of wood are compared with the virtual individualising characteristics saved in the database for virtual pieces of wood, in order to identify a match; and an identifying step, during which an origin of the real piece of wood is identified based on the information about the identity of the log which is saved in the database together with the virtual individualising characteristics of a virtual piece of wood which match the real individualising characteristics of the real piece of wood.