[en] The excited state dynamics and electron transfer reactions of luminescent probes bound to hosts with different properties provide a means to compare the systems. Although photoinduced electron transfer reactions between photoexcited ruthenium(II)-poly pyridines and various acceptors have been known in the literature, relatively a few reports are available on reactions with cobalt(III) complexes as quenchers. The current interest in ruthenium-poly pyridines and micro heterogeneous systems such as micelles and DNA led us to study the effect of micelles on the quenching of the emission of *Ru(bpy)₃²⁺ by some cobalt(III) amine complexes. The results obtained on the photochemical electron transfer between excited Ru(bpy)₃²⁺ and several cobalt(III) amine complexes by emission quenching studies in ordinary aqueous solution as well as in micellar solutions have been presented in this report. (author)