phospha-Michael reaction of diphenyl phosphonate to nitroolefins was achieved by utilizing a 1,3-diamine-tethered guanidinium/bisthioureaorganocatalyst. The procedure is applicable to nitroolefins having various aromatic and aliphatic substituents, and enables an efficient access to phospha-Michael products with 90–98% ee. Monomeric or oligomeric active species of the catalyst can be utilized, depending