The ligands L = pyridine- or quinoline-carboxylic acid easily give complexes trans-[PdCl2L2], which self-assemble through hydrogen bonding between carboxylic acid groups to give one-dimensional polymers, as proved by structure determinations when L = NC5H4COOH-4, NC5H4COOH-3, and 2-Ph-NC9H5COOH-4.Key words: polymer, hydrogen-bonding, palladium, coordination.