This paper deals with fully grouted rockbolts, both for mining and civil engineering applications. Their mechanical behavior under tensile loads is reviewed theoretically and experimentally. As for the theoretical part, a new solution able to predict the full range behavior of a grouted bolt subjected to a pull-out test is explained. The originality of the new approach lies in the fact that the boundary conditions only concern the free end of the bolt. The experimental part consists of a wide pull-out test campaign performed in laboratory on deformed steel bars and on FRP rockbolts. These tests have been carried out using a new experimental bench, whose main assets will be described. The influence of several parameters such as the confining pressure, the bolt profile and the quality of the grouting material has been considered. The results of these tests will help in the derivation of a constitutive law for the rockbolt-grout interface. In situ pull-out tests conducted in ANDRA’s URL in North-Eastern France to examine the performance of different bars have also been analyzed and compared to the laboratory-scale results.