The X-ray structure analysis of 1:1 crystal complex of decyltrimethylammonium chloride with rac-1,1'-bi-2-naphthol (hereafter, 10TAC/BNP) yielded a triclinic lattice with [image omitted] symmetry, formula C33H42NClO3, formula weight 536.15, crystal size 0.10x0.20x0.10mm3, a=9.999(1) angstrom, b=19.420(1) angstrom, c=8.977(9) angstrom, =92.845(8)degrees, =112.718(7)degrees, =98.396(7)degrees, V=1579.9(3) angstrom 3, Z=2, calc=1.135g cm-3, 2max=120.2 degrees, m.p=168.7 degrees C, and the asymmetric unit consists of a molecule each of 10TAC, BNP, and water. The crystal structure shows a distinct similarity in the packing structure observed in crystal complexes of monoalkyltrimethylammonium halides with planar aromatic molecules. The arrangement of the naphthol planes as per controlled by the hydrogen bond network plays significant role in the packing structure. The combined actions of hydrogen bonding, electrostatic interactions and C-H... interactions contribute to the stability and formation of the crystal complex.