This study reports on a method for influencing the thermal isomerization of azobenzene-based acrylic monomers and (co)polymers by means of interaction between basic polymeric and monomeric azobenzenes (modified with a basic dimethylamino substituent, (polyazobases) and (poly)acids. The results indicate that acid catalysis is the predominant effect, which is controlled by (inter)polymer cooperative hydrogen bonding, because on addition of the low molecular weight isobutyric acid (IBA) to the (polyazobases no effect was observed, and on addition of poly(methacrylic acid) (PMA) to the monomeric azobases only a weak effect was found. On addition of PMA, the rate constant of the thermal cis to trans isomerization (k(T-isom)) of a polyazobase could be enhanced by a factor of 70. The influences of factors like copolymer composition, spacer length, solvent type, and stabilization time after mixing on the thermal isomerization were also investigated and explained in terms of polymer complexation. In the absence of PMA the rate of the thermal isomerization was found to decrease by introduction of a spacer, by lowering the azobase monomer content in copolymers and by improving the solvent quality. The results on the thermal cis to trans isomerization presented here were obtained from measurements in dilute solution with concentrations well below c*, because in that case polymer matrix effects could be ruled out.