We report the synthesis of the compound [Mn(tacn)]2[Mo(CN)7]·5H2O, another addition to the family of MnMo-heptacyanates. It is obtained by capping the Mn(II) with the ligand ‘tacn’ (triazacyclononane) and reacting it with the [MoIII(CN)7]4− precursor. It exhibits ferromagnetic behavior below 90 K.