Chloronitroaromatic compounds are widely used as important building blocks for the chemical synthesis of pesticides, herbicides, dyes etc [1]. Recently, chloronitrobenzoic acids have been listed in a novel therapy for immunodeficiency diseases [2]. In this research we investigate structural aspects of ethanolamine salts of 2-chloro-4-nitrobenzoic acid (I) and 2-chloro-5nitrobenzoic acid (II), focusing on hydrogen bonding interactions and investigates molecular packing in crystalline salts. Compounds have been prepared in diethylether solution and crystallized in monoclinic space group P21/c, a=8.402(2), b=6.664(1), c=22.023(4)Å, β=100.72(3), with Z=4 (I) and triclinic space group P-1, a=7.019(1), b=9.512(2), c=9.740(2)Å, α=79.19(3), β=88.58(3), γ=78.42(3), with Z=2 (II). Note that even if the compounds differ only by the position of the substituents, compound II crystallized as hydrate, which changes the system of hydrogen bonds. The salt units of all compounds serve as building blocks of the supramolecular architecture. In compound I, ethanolammonium cation forms three hydrogen bonds (two N-H…O and one O-H…O) with three 2-chloro-4-nitrobenzoate anions, while in compound II, ethanolammonium cation forms only two hydrogen bonds (one N-H…O and one O-H…O) with two 2-chloro-5-nitrobenzoate anions. In addition, the two components of compound II are linked between them by a water molecule, which acts as donor in two hydrogen bonds O(W)-H…O with benzoate anion, and acceptor in a hydrogen bond N-H…O(W) with ethanolammonium cation. In both compounds, the anions, cations and water molecules (only II) form hydrogen bonded chains, which further are consolidated into layers. The present work may give some insight to the design of new molecular materials of desired architectures.figure