The delignification and subsequent densification of wood has been repeatedly demonstrated as being a useful and efficient route to improving the mechanics of wood and non-wood materials. Own work has shown that while delignification and densification almost always improve wood tensile mechanics in fiber direction, the side effects of the process with regard to bending strength, transverse strength and adhesive bonding are less studied. Also, most of literature applies rather harsh chemical treatment, focusing on almost complete removal of lignin. Own work with hardwood has shown that delignification is not always required and that significant improvements in strength can also be achieved by focusing on mild extraction of non-cellulosic cell wall polysaccharides. Thus, in the present paper, we briefly summarize our experience from five years of work on delignification and densification of wood and non-wood materials.