Reaction of decamethylchromocene (Cp*2Cr) with thioindigo (TI) yields a coordination complex {[TI-(μ2-O), (μ-O)]Cp*Cr}2·C6H14 (1) in which one Cp* ligand in Cp*2Cr is substituted by TI. TI adopts cis-conformation in 1 allowing the coordination of both carbonyl groups to chromium. Additionally, one oxygen atom of TI becomes a μ2-bridge for two chromium atoms to form {[TI-(μ2-O), (μ-O)]Cp*Cr}2 dimers with a CrCr distance of 3.12 Å. According to magnetic data, diamagnetic TI2- dianions and two Cr3+ atoms with a high S = 3/2 spin state are present in a dimer allowing strong antiferromagnetic coupling between two Cr3+ spins with an exchange interaction of -35.4 K and the decrease of molar magnetic susceptibility below 140 K. Paramagnetic TI˙- radical anions with the S = 1/2 spin state have also been obtained and studied in crystalline {cryptand[2,2,2](Na+)}(TI˙-) (2) salt showing that both radical anion and dianion states are accessible for TI.