Three heterometallic coordination polymers based on 4-amino-1,2,4-triazole (atrz), Cd2.98Fe2.02(atrz)6(SCN)10·2H2O (1), Cd2.86Co2.14(atrz)6(SCN)10·2H2O (2), and Cd2.02Ni2.98(atrz)6(SCN)10·2H2O (3), were synthesized. Crystal structures of the polymers were determined by single-crystal X-ray diffraction, X-ray powder diffraction, and infrared analysis. The complexes exhibit a 3-D structure and are isostructural, but entail different durations for transformation from a 1-D polymer to a 3-D structure. The results of vibrating sample magnetometry for 1 indicate that the complex exhibits weak paramagnetism.