Reaction of RhCl(PPh3)3 with [MeH2NNH2Me]Cl in MeOH gives [(MeOH)2H][RhCl4(PPh3)(NHMeNHMe)], which was characterized by x-ray crystallog. [triclinic space group P.hivin.1, a 16.430(3), b 9.848(2), c 9.850(2) .ANG., .alpha. 117.79(2), .beta. 75.99(2), .gamma. 45.15(2).degree., Z = 2; R = 0.0393 for refinement of 3491 data with I > 1.5.sigma. (I)]. The complex anion has an octahedral structure with the phosphine and hydrazine ligands mutually trans and is formulated as a Rh(III) species on the basis of the bond lengths in the structure and its diamagnetism. The compensating cation is a proton which, although not unequivocally identified in the structure, is presumed to be present as a dimethanolium unit, in which the O...O distance is 2.67 .ANG..