A dendrimer of tris(2-aminoethyl)amine (TREN), containing six diglycolamide (DGA) pendent arms (TREN-G1-DGA), was evaluated for the extraction of different actinides and Eu3+ ions in a methylimidazolium-based room temperature ionic liquid (RTIL; C4mim·NTf2). The results indicated a significant enhancement of the extraction of the trivalent metal ions Am3+ and Eu3+ in the RTIL medium as compared to that in molecular diluents, whereas in the case of the tetravalent actinides Pu4+ and Np4+ the extraction was least affected by the diluent media. This is explained based on a different extraction mechanism for the trivalent and the tetravalent metal ions. The extraction behaviour was well corroborated with the help of a luminescence study.