The enthalpies of solution Delta H-sol(m)m were determined for 1,1,3,3-tetramethylurea in ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol (2-methyl-2-propanol). Measurements were made at 298.15 K and molalities m congruent to (0.007 to 0.036) mol . kg(-1) with a precise iso- peribol ampoule-type calorimeter. Standard enthalpies of solution Delta H-sol degrees(m) and transfer Delta H-sol degrees(m) from one alkanol to the other (including methanol) were calculated. The obvious relationship between the enthalpic and volumetric effects of solution of tetramethylurea in the n-alkanols (C-1-C-4) was discovered. The enthalpic effects of transfer caused by branching of the alkanol molecules, 1-propanol -> 2-propanol, and 1-butanol -> t-butanol, are opposite in sign and dominated by the configurational changes in the solvation environment of tetramethylurea. (C) 2007 Elsevier Ltd. All rights reserved.