Viscosities eta of dilute solutions of n-propylamine, n-butylamine, di-n-propylamine, di-n-butylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine in 1-butanol and 2-butanol at 303.15 K have been measured. The specific viscosities (eta - eta(S)degrees)/eta(S)degrees and viscosity deviations Delta eta have been calculated. The values of (eta - eta(S)degrees)/eta(S)degrees and Delta eta are negative and their magnitude increases with the increase in concentration of alkylamine. The values of excess Gibbs energy of activation Delta G*(E) of viscous flow determined based on Eyring's theory of absolute reaction rates are positive for alkylamine solutions in both the butanols. The strong solute-solvent interactions leading to the structure formation between butanol and alkylamine molecules through H-bondings are observed. The results have been further analyzed in terms of Herskovits and Kelly equation and Nakagawa equation. The values of viscosity increment ( in Herskovits and Kelly equation and coefficient B-int' in Nakagawa equation are negative for all presently investigated alkylamine solutions. (C) 2009 Elsevier B.V. All rights reserved.