The reaction of MnCl2 center dot 4H(2)O with 2-aminoethanethiol (=Haet) under anaerobic conditions afforded yellow plate crystals of octanuclear manganese complex [Mn-4(mu(4)-O){Mn(aet)(3)}(4)]Cl-2 center dot MeOH center dot 4H(2)O. A complex molecule consists of four fac(S)-[Mn(aet)(3)] units linked to Mn-4(II)(mu(4)-O) core by thiolato bridges. Magnetic susceptibility measurements revealed the presence of antiferromagnetic interactions through mu(4)-oxo and mu(2)-thiolato bridges.