The RGL protein, a homolog of the Ral GDP dissociation stimulator (RalGDS), has been identified as a downstream effector of Ras. In the present study, the solution structure of the Ras-binding domain of RGL (RGL-RBD) was determined by NMR spectroscopy. The overall fold of RGL-RBD consists of a five-stranded beta-sheet and two alpha-helices, which is the same topology as that of RalGDS-RBD. The backbone chemical shift perturbation of RGL-RBD upon interaction with the GTP analog-bound Ras was also examined. The solution structure of RGL-RBD, especially around some of the Ras-interacting residues, is appreciably different from that of RalGDS-RBD.