In vitro grafting is a relatively recent vegetative propagation technique which consists of grafting miniaturized scions in axenic culture conditions. It combines thus the advantages of grafting and of shoot tip culture, while overcoming certain limitations of these two methods. Several in vitro grafting procedures can be considered, differing one from another by the type of grafting technique used, and also by the characteristics of the in vitro rootstock and scions involved. Initially developed for eradicating endogenous pathogens from fruit tree species and cultivars, in vitro grafting has been rapidly extended to various woody species in different domains of plant physiology and improvement. These encompass grafting incompatibility and also physiological rejuvenation as a prerequisite for mass clonally propagating mature selected genotypes of most woody species. In conclusion, in vitro grafting is an original and skilful technique which should deserve more consideration for overcoming the limitations of more common other vegetative propagation methods, and also for studying more in depth the relationships between genetically different tissues and cells.