The asymmetric unit of the title compound, {[Cu(C(4)H(2)O(4))(C(3)H(10)N(2))(H(2)O)]·H(2)O}(n), consists of two Cu(II) atoms, half each of two propane-1,3-diamine ligands and two coordinated water mol-ecules, all lying on crystallographic mirror planes, also one fumarate dianion and one uncoordinated water mol-ecule in a general position. The Cu(C(3)H(10)N(2))(H(2)O) units are linked via fumarate dianions into a zigzag chain running along the a axis. A longer Cu-O distance [2.873 (3) Å] is to a water mol-ecule bridging equivalent Cu(II) atoms in adjacent chains, forming a three-dimensional framework. One of the Cu(II) atoms is in a distorted square-pyramidal environment and the other is in a pseudo-octa-hedral geometry of the [5+1] type. O-H⋯O and N-H⋯O hydrogen bonds are observed in the crystal structure.