The structures of cocrystals of 5-aminoisophthalic acid (AIA) with various quinoline derivatives are investigated. The cocrystals of AIA with isoquinoline are comprised of dimers of carboxylic acids end capped by isoquinoline molecules. The repeat units have length 30.05 angstrom each. The hydrated cocrystals of AIA with quinoline and 8-hydroxyquinoline are structurally characterized and they have four and six coordination environment around water molecules respectively. The cocrystal of 4-hydroxyquinazoline with AIA has sheet like structure with repeated dimeric carboxylic acids possessing R-2(2)(14) type of H-bond patterns. In thermogrvimetry, the cocrystals of 5-aminophthalic acid with quinoline or 8-hydroxyquinoline loses the quinoline counterparts followed by decarboxylation of the parent acid, the decarboxylation takes place at 275 degrees C-450 degrees C.