The interaction of sodium dimethyldithiocarbamate with acetone solutions of chlorotris(triphenylphosphine)rhodium(I) and trans-chlorocarbonylbis(triphenylphosphine)rhodium(I) leads to the new complexes RhI(S2CNMe2)(PPh3)2, RhI(S2CNMe2)(CO)PPh3, RhIII(S2CNMe2)3(PPh3), and RhIII(S2CNMe2)3(CO)PPh3. I.r. and n.m.r. spectra of the last two complexes suggest the presence of a unidentate dithiocarbamate group. From chlorodicarbonyl-π-cyclopentadienyl-iron(II) a similar unidentate complex (π-C5H5)Fe(CO)2(S2CNMe2) has been obtained. Dichlorotris(triphenylphosphine)ruthenium(II) reacts with sodium dimethyldithiocarbamate, the corresponding diethyl and diphenyl salts, and also sodium O-methyl and -ethyl dithiocarbonates to form ruthenium(II) chelate complexes of the type Ru(Me2NCS2)2(PPh3)2 and Ru(MeOCS2)2(PPh3)2.