Making an adequate root canal filling, a biocompatible and hermetically sealing filling just to the apical constriction, is a relatively difficult and time-consuming task. A variety of materials and techniques are available. In this article an overview is given of some well-known materials and techniques. It is concluded that those techniques have to be selected on which the dentist can rely and with which he gets consistently radiographically adequate root fillings and clinically favourable results. The choice of root filling in practice will depend on the nature and shape of the canal to be treated. For this reason it is advised that the dentist masters several techniques.