Wood is a renewable natural resource that provides raw material for construction, power generation, fibers for pulp and paper production, panels and boards, and more recently, biofuels and biomaterials, making it the fifth most important commercial product in the world. The wood is a highly variable and complex material that has different chemical, physical and anatomical properties that are influencing their commercial value. These properties depend on the size, shape and arrangement of the different cell types, and of the structure and chemical composition of the xylem cell wall. At the same time, these properties are controlled by different environmental and genetic factors that regulate the biosynthesis processes of the different wood components. To apply molecular and genetic tools to optimize the selection processes of forest species with superior traits, it is necessary to understand the mechanisms that regulate these properties, as the dynamics of cell wall structure from the initial cambial cell formation to the final differentiated cells formation that compose the xylem. This review explores the main anatomical traits and the xylogenesis processes, particularly focused in angiosperms, discussing the genetic aspects involved in the determination of wood anatomical characteristics, as cellular elements and fiber characteristics, based on different studies with species of the Populus and Eucalyptus genus, besides the model plant Arabidopsis thaliana.