<p>The polymerization of methyl methacrylate in the presence of 3-amino-7-dimethyl-amino-2-methylphenazine as a phenazine photocatalyst and <i>tert</i>-butyl bromide as an initiator was studied. It was shown that this dye, in both neutral and protonated forms, is capable of initiating radical polymerization when exposed to visible light, both under anaerobic conditions and in the presence of atmospheric oxygen. The effect of the solvent on the processes under study was assessed and it was established that polymerization occurs according to the metal-free atom transfer radical polymerization (ATRP) scheme of the oxidative type only in polar solvents. Under the reductive type metal-free ATRP conditions, both the protonated and neutral forms of 3-amino-7-dimethylamino-2-methyl-phenazine acted as catalysts regardless of the solvent nature, with the efficiency of the catalytic system increasing as the polarity of the medium, in which the polymerization process takes place, increased.</p>