Viscosities, 77, of dilute solutions of n-propylamine, n-butylamine, di-n-propylamine, di-n-butylamine, tri-n-propylamine, and tri-n-butylamine in cyclohexane, benzene at 303.15 and 313.15 K and of triethylamine in n-heptane, cyclohexane, benzene, toluene, ethylbenzene and p-xylene at 303.15 K have been measured. The specific viscosities, (eta - eta(s)(0))/eta(s)(0), and viscosity deviations, Deltaeta, have been calculated. Based on Eyring's theory of absolute rea,ction rates, the values of excess Gibbs energy of activation, DeltaG(*E), of viscous flow has been determined. The results have been analysed in terms of Herskovits and Kelly equation and Nakagawa equation. (C) 2004 Elsevier B.V. All rights reserved.