dGMP, dAMP, dCMP and dTMP were incubated with cis PDD in a nucleotide/Pt ratio 1:1 for 72 h. Following hydrolysis, Pt derivatives of the bases were separated on Sephadex G10 columns. dGMP, dAMP and dCMP reacted with cis PDD but only dGMP reacted completely. All the nucleotides mentioned above formed adducts with cis PDD with a metal to ligand ratio 1:1. Moreover an ML2 complex was isolated after the reaction of dGMP with cis PDD. These Pt-base(s) complexes were eluted from the columns in separate peaks. UV spectra of the complexes differed from the standard ones. In some peaks, eluted separately from the standards, no Pt was detected. The samples eluted in these peaks had UV spectra different from the standards. They may represent products of base degradation.