In the title compound, [Co(C(20)H(18)P)I(C(3)H(9)P)(2)], the Co(II) atom has a distorted square-pyramidal geometry, the base of which is comprised of two trans PMe(3) groups, an I atom, and a C atom of the benzyl group. This benzyl group is tethered to the P atom at the apex of the pyramid, thereby forming a five-membered chelated Co-C-C-C-P ring.