The title salt, (PnH2)2(Btc)2H2O or 2C3H12N2 2+C10H2O8 4- 2H2O, has been prepared from propane-1,3-diamine (Pn) and benzene-1,2,4,5-tetracarboxylic acid (BtcH4). A wide range of noncovalent interactions, consisting of ion pairing and hydrogen bonding with D A distances ranging from 2.7075 (15) to 2.9726 (15) A ˚ , connect the various components into a supramolecular structure.