Let F be an infinite field of characteristic different from 2 and G a group. We examine the set of units, \({\mathcal{U}}^{+}(FG)\), symmetric under the natural involution ∗ sending each group element to its inverse. The conditions under which \({\mathcal{U}}^{+}(FG)\) satisfies a group identity are presented, subject to the restriction that G ∕ T is a u.p. group for the sufficiency, where T is the set of torsion elements of G.