In the title compound, C(21)H(23)NO(3), the central oxazolidinone ring is approximately planar, the maximum deviation from the plane through the central ring being 0.043 (1) Å. The tert-butyl and benzyl substituents are cis to each other and trans to the N-benzoyl group. The inter-planar angle between the aromatic rings of the C-benzyl and N-benzoyl groups is 81.10 (4)°.