Solid + liquid phase diagrams have been determined for 1-octanol, 1-nonanol, 1-decanol, or 1-undecanol + decylamine mixtures. Solid addition compounds form with the empirical formulas: C8H17OH.C10H23N, C9H19OH.C10H23N, C10H21OH.C10H23N, and C11H23OH.C10H23N. All are congruently melting compounds. Compound formation is attributed to a strong A-B interaction. The excess molar volumes, V-m(E), have been determined for these mixtures at 298.15 K and atmospheric pressure. The systems exhibit very large negative excess molar volumes, V-m(E), and excess molar enthalpies, H-m(E). The V-m(E) curves are nearly symmetrical. Strong cross association between hydroxyl and amine groups ((OHNH2)-N-...) is a dominant effect, and it causes high negative values of V-m(E) and H-m(E) and 1:1 congruently melting solid compounds at lower temperatures. Our experimental data on V-m(E) and the literature data on H-m(E) were treated in terms of the ERAS model, DISQUAC, and modified UNIFAC. The ERAS model consistently describes V-m(E) and H-m(E) of the studied mixtures.