The crystal structure of the title compound, [Rh(C(6)H(19)N(4))Cl(3)]Cl·0.5H(2)O, is isotypic with the previously reported Ru analogue. The structure contains two crystallographically independent [Rh(Htren)Cl(3)](+) cations with a facial tridentate coordination of the monoprotonated tren ligand [tren = tris-(2-amino-eth-yl)amine], leading to an overall distorted octahedral coordination environment around the Rh(III) atom. In one of the two cations, the ethyl-ene groups of the two chelate rings as well as the non-coordinating ethyl-ammonium group are disordered over two sets of sites [0.579 (3):0.421 (3) occupancy ratio]. A series of N-H⋯Cl and O-H⋯Cl hydrogen bonds stabilizes the structure.