Nanosized coordination polymers of Co(II), Ni(II), Cu(II) and Cd(II) of mixed ligand derived from 5-(3-pyridyl)-1,3,4-oxadiazole-2-thiole (POZT) and 2-aminothiazole (AZ) were synthesized. The compounds were characterized by elemental analysis, IR and electronic spectral studies. Thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) have been used to study the thermal decomposition steps of the compounds and to calculate the thermodynamic parameters of the nanosized metal coordination polymers. The kinetic parameters have been calculated making use of the Coats-Redfern and Horowitz-Metzger equations. The scanning electron microscope SEM photographs and particle size calculations from the powder XRD data indicate the nano-sized nature of four compounds prepared under ultrasonic irradiation (average size 23-60 nm). The antimicrobial activity of the synthesized compounds was tested against six fungal and five bacterial strains. The majority of compounds were effective against the tested microbes