The asymmetric unit of the title compound, [Mg(H(2)O)(6)](C(9)H(7)N(4)O(2)S)(2), contains one-half of a [Mg(H(2)O)(6)](2+) cation ( symmetry) and one uncoordinated 2-[(1-phenyl-1H-tetra-zol-5-yl)sulfan-yl]acetate anion. The Mg(II) cation is coordinated by six water mol-ecules, exhibiting a slightly distorted octa-hedral coordination. A two-dimensional network parallel to (001) is formed via extensive hydrogen-bonding inter-actions involving the water mol-ecules as donors and the tetra-zole N and carboxyl-ate O atoms of the anion as acceptors. The shortest distance between two adjacent parallel benzene rings is 3.315 (2) Å. The dihedral angle between the benzene ring and the tetra-zole ring is 40.98 (2)°.