In the title compound, C(18)H(24)N(2)O(2)S, the thia-zolidinone ring is almost coplanar [maximum atomic deviation = 0.017 (3) Å], and is coplanar with the phenyl ring [dihedral angle = 0.62 (13)°]. The octyl group displays an extended conformation. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into supra-molecular chains along [210].