A cyano-bridged ferromagnetic {Fe(III)Ni(II)} alternating chain {[Fe(pzTp)(CN)3][Ni(chxn)2]}·ClO4·H2O (1) (pzTp = tetrakis(pyrazolyl)borate, chxn = (1R,2R)-1,2-diaminocyclohexane) was synthesized via rational design. Crystal structure analysis and magnetic studies demonstrated that compound had a one-dimensional zigzagging chain-like structure and slow magnetic relaxation.