The title complex, [Cu(C(12)H(8)N(2))(2)]I, (I), has been crystallized in two polymorphic forms, both containing four-coordinate copper. Both forms are orthorhombic, with form (Ia) crystallizing in the primitive space group Pban and form (Ib) in the c-centred space group Ccca. In (Ia), the complex cation and the I(-) anion both have 222 crystallographic symmetry, and in (Ib), the complex cation has approximate 222 symmetry, with the I(-) counter-ion distributed over three special positions.