The title compound, C(19)H(31)O(2)P, features a distorted tetra-hedral P atom that bonds to the phenyl ring, isopropyl and 2-isopropyl-5-methyl-cyclo-hexyl groups, and is determined as having an R(p) configuration. A chair conformation is observed for the cyclo-hexyl ring. In the crystal, mol-ecules are linked into chains running along the a axis by weak inter-molecular C-H⋯O hodrogen bonds.