The crystal structure of two semiflexible dicarboxylic acids forming chains is reported; these compounds are models for the crystal packing of polyesters based on 1,5- or 2,7-dihydroxynaphthalene and aliphatic dicarboxilic acids and, more generally, for crystal packing of semiflexible chains containing conformationally blocked aromatic cores along the chain. In both crystal structures, chain axes are not parallel to each other, this unusual feature being connected, seemingly, with the lateral packing of aromatic cores present in the molecules.