Electrochemical oxidation of 4-morpholinoaniline (4MA) in six nonaqueous solvents was carried out using cyclic voltammetry technique. Two one-electron transfer couples were observed with a half-wave potential separation (Delta E-1/2) which is consistent with the donor number of solvents. In these solvents, in scan rates (0.1-1 Vs(-1)), the first oxidation step of 4-morpholinoaniline was found to be diffusion controlled with chemically reversible process. Significant differences in the chemical reversibility were observed for the second oxidation step. In donor solvents such as DMSO, DMF and THF, the oxidation of 4MA(center dot+) to the dication (4MA(2+)) is coupled with chemical follow-up reactions. Also the solvent effects on the heterogeneous electron exchange of 4MA to radical cation (4MA(center dot+)) have been studied in nonaqueous solvents. In addition, the effect of the physical and chemical properties of the solvent on the electrochemical behavior of the 4MA/4MA(center dot+) couple has been examined. Values of the heterogeneous electron transfer rate constants (k(s)) were determined through cyclic voltammetry by applying digital simulation method. It has been shown that the dynamics of solvent reorientation strongly affects the heterogeneous electron transfer rate in the studied case. An almost linear relationship between ln k(s) and ln tau(L), the longitudinal relaxation time of a given solvent has been found. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.014208jes] All rights reserved.