The meso-dithioxamide H-((R)-1-(1-phenypethyl)-NSC CSN-((S)-1-(1-phenypethyl)-H (H-2-mesoDTO) bonds [(eta(6)-p-cymene)chlorido-ruthenium(II)](+) or [(eta(3)-allyl)-palladium(ll)](+) fragment and provides the C-s symmetrical complexes [(eta(6)-p-cymene)CIRu(H-mesoDTO K-S,S Ru)] (1) and [(eta(3)-allyl)palladium(H-mesoDTO K-S,S Pd)] (2). These complexes are pseudochiral, and each of them exists as a mixture of two symmetrical meso forms. The improper symmetry of [(e-allyl)palladium(H-mesoDTO K-S,S Pd)] has been broken in two different ways: (i) by changing the symmetrical allyl moiety with a eta(3)-crotyl frame or (ii) by substituting the residual amidic hydrogen in the dithiooxamidate ligand with a M(PR3)Cl+ fragment (M = Pd or Pt and PR3 = triorganophosphine). As a consequence, a chiral plane is added to the pseudochiral palladium center, and two pairs of enantiomers are formed in each case. Furthermore, [(/76-p-cymene)chlorido-ruthenium(11)] and [(173-ally1)-palladium(11)] fragments have been joined by means of the binucleating meso-dithiooxamidate ligand in a K-S,S Ru K-N,N Pd coordination mode. The resulting C-s-symmetrical complex [(eta(6)-p-cymene)CIRu(mu-mesoDTO K-S,S Ru K-N,N Pd)Pd(eta(3)-allyl)] (8) possesses two pseudochiral metal centers, and it is therefore a mixture of four isomeric meso forms. All of these isomers in a chloroform solution interconvert in that both palladium and ruthenium invert their configurations. A mechanism of epimerization for both palladium and ruthenium is proposed. The absolute configurations of pseudochiral palladium in [(eta(3)-allyl)(c)-Pd(mu-((R)-1 -(1 -phenypethyl)-NSC CSN-((S)-1 -(1 -phenypethyl) K-N,N (c)-Pd K-S, S (A,C)-Pd)(A,C)Pd(tri(n)propyl-phosphine)Cl] (6) and of pseudochiral palladium and ruthenium in [(eta(3)-allyl)(c)-Pd(mu-((R)-1-(1-phenyl)ethyl)-NSC CSN-((S)-1-(1-phenyl)ethyl) K-N, N (c)-Pd K-S, S(s)-Ru)(s)-Ru(eta(6)-isopropyltoluene)Cl] (8) are provided. A suitable stereochemical notation is proposed for bimetallic complexes containing pseudochiral centers in either a chiral or an achiral environment.