Abstract By the combined use of the steady-light experiment and a flash technique, photoreduction of phenazine in methanol, ethanol, isopropanol and by EDTA in the aqueous solution and also the related elementary processes have been studied. The photoproduct has been identified as dihydrophenazine of which the absorption spectrum has been measured for the first time. It has been concluded that the lowest triplet, T(π–π*) is not a reactive state. Most probably the reactive state is a higher T(n−π*). The quantum yields of photoreduction in methanol, ethanol, and isopropanol are respectively 0.023, 0.037 and 0.050. Singlet-Triplet transition probability (ΦST) has been found to be >0.33 in the aqueous solution. Semiquinone produced in alcohols disappears by disproportionation reaction with almost the diffusion controlled rate constant while in the aqueous solution the disproportionation is much slower and at high EDTA concentrations, semiquinone is further reduced by EDTA. The absorption due to a molecular compound consisting of phenazine and dihydrophenazine has been detected in the visible region. It has been suggested that a certain equilibrium exists between three compounds and that a rather stable radical species, the existence of which has been proved by an ESR spectroscopy, participates in this equilibrium.