The use of diffusion NMR measurements in the field of coordination chemistry is nowadays boosted by the extraordinary progress achieved in the study of various supramolecular architectures or smaller metallic complexes, allowing one to assess the aggregation state, character of intermolecular interactions, stability or association constants between different hosts and guests [1]. We present herein the results of our investigations on the application of the Diffusion Ordered SpectroscopY (DOSY) method on seven coordination polymers [Zn(I)2(4-bpmhz)]n (1), [Cd(I)2(4-bpmhz)]n (2), [Zn(I)2(3-bpmhz)]n (3), [Cd(I)2(3-bpmhz)2]n (4), [Zn(NO3)2(H2O)2(4bpmhz)]n·0.5n(EtOH) (5), [Cd(NO3)2(4-bpmhz)3/2(MeOH)]n·0.5nH2O (6) and [Zn(NO3)2(3bpmhz)2]n (7) that were derived from methylated azine ligands of the bis-monodentate N,N'donor type, 1,2-bis(1-(pyridin-4-yl)ethylidene)hydrazine (4-bpmhz) and 1,2-bis(1-(pyridin-3yl)ethylidene)hydrazine (3-bpmhz). Compounds 1-7 were characterized in the solid state by single-crystal X-ray structural analysisand in solution by spectroscopic methods [2]. Roomtemperature (298K) diffusion experiments on coordination polymers 1-7, as well as 4-bpmhz and 3-bpmhz ligands were conducted to determine the size of molecular systems in DMSO-d6 solution. The translational diffusion coefficient value (D), which is a function of the molecular size and shape, was determined for metallic complexes 1-7 and their ligands in solutions of different molarities. The D values of DMSO-d6 molecules were used as reference in the cases of all studied samples. For all solutions the ratio DDMSO-d6/Dcompound was calculated. After processing the experimental data that included comparison of the ratio DDMSO-d6/Dligand to the ratio DDMSO-d6/Dcompound, the values varying from 84% and 96% were calculated for all samples. The obtained data are favorable to the presence in solutions of complexes 1-7 of the species with the molecular size comparable to that of free ligands. The obtained results point to the dissociation of the 1D chain structures of polymers 1-5 and 7 and 2D coordination networkof 6in DMSO-d6 solutions. For calculation of D the StokesEinstein equation has been used [3].