In the crystal structure of the title compound, [Cd(C8H7O2)(2)(C6H6N2O)(2)(H2O)]center dot H2O, the Cd-II cation is coordinated by two 4-methylbenzoate (PMB) anions, two isonicotinamide (INA) ligands and one water molecule in a distorted octahedral CdN2O4 geometry. One of PMB ions acts as a bidentate ligand while the other and the two INA are monodentate ligands. An O-H center dot center dot center dot O hydrogen bond links the uncoordinated water molecule to the carboxyl groups of the complex. The dihedral angles between the carboxyl groups and the adjacent benzene rings are 10.28 (11) and 21.24 (9)degrees, while the two benzene rings and the two pyridine rings are oriented at dihedral angles of 6.90 (4) and 88.64 (4)degrees, respectively. In the crystal structure, O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds link the molecules into a supramolecular structure. A pi-pi contact between the benzene rings [centroid-centroid distance = 3.911 (1) angstrom] may further stabilize the crystal structure. Weak C-H center dot center dot center dot pi interactions involving the pyridine rings also occur in the crystal structure.