Bianthrone exists in two forms which are in thermochromic equilibrium. Earlier studies have shown that the twisted high temperature B-form is more readily reduced than the doubly-folded, low temperature. A-form, At room temperature the A-form is reduced in an ECE sequence: A → AXXX → BXXX → B2- At higher temperature the reaction can proceed by prior conversion of A to B followed by reduction, i,e. a CEE scheme A → B → BXXX B2-. In the present paper it has been found that the disproportionation/reproportionation (DISP/REP) equilibrium (B2- + B ⇌ 2BXXX) has a pronounced effect on the cyclic voltammograms. Results for the reduction of bianthrone in bezonitrile have been quantitatively interpreted in terms of the CEE scheme with associated DISP/REP equilibrium. The values of equilibrium and rate parameters obtained are in excellent agreement with previous studies.