Azoxybenzenes (1) were heated at 245–250 °C to give azobenzenes (2), 2-hydroxyazobenzenes (3), 2-hydroxy-azoxybenzenes (4), 4-hydroxyazobenzenes (5), and 4-hydroxyazoxybenzenes (6). Compounds 4 and 6 were mostly composed of α-isomers. In the reaction of azoxytoluenes, their methyl groups were oxidized to formyl groups. It was proposed that 4 and 6 were the intermediates of the thermal rearrangement