Excess molar volumes V(E) at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of (heptane + open chain secondary (diethyl to dibutyl) and tertiary (triethyl to tripentyl) amines) as well as for cyclic imines (C(2), C(3), C(4), C(6), and C(7)) and primary cycloalkylamines. (C(5), C(6), C(7), and C(12)). The V(E) values were found positive for mixtures involving small size amines, with V(E) decreasing as the size increases. Negative V(E)'s were found for tributyl- and tripentylamine, heptamethylenimine, and cyclododecylamine. Mixtures of heptane with cycloheptylamine showed an s-shaped curve. Partial molar volumes V of amines at infinite dilution in heptane were obtained from V(E) and compared with V of hydrocarbons and other classes of organic compounds taken from literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH(3), CH(2), CH, C, NH(2), NH, N, OH, O, CO, and COO) contributions to V(o). These contributions, the effect of cyclization on V(o), and the limiting slope of the apparent excess molar volumes were discussed in terms of solute-solvent and solute-solute interactions. (C) 2011 Elsevier Ltd. All rights reserved.