Irradiation in the LF bands (1)A(1) --> (1)E(1) and (1)A(1g) --> (1)A(2g), (1)E(g) leads to NH3 photolabilization of trans-[Ru(NH3)(4)(P(III))H2O](2+) complexes and to NH3 and P(III) photolabilization of trans-[Ru(NH3)(4)(P(III))(2)](2+) species. For both series of complexes Phi(NH3) has essentially the same experimental value of 0.34 +/- 0.03 mol/einstein. The Phi(P(III)) values for the bis(phosphane) complexes trans-[Ru(NH3)(4)(P(III))(2)](2+) are in the 0.034-0.070 range for P(III) = P(OCH3)(3) and P(OC2H4Cl)(3). No clear relationship could be established between the cone angle theta of the phosphane or the formal potential E degrees’(Ru(III)/Ru(II)) and the corresponding Phi(NH3) and Phi(P(III)) data for the complexes studied. The NH3 ligand is selectively photolabilized when the trans-[Ru(NH3)(4)(P(III))(2)](2+) and the trans-[Ru(NH3)(4)(P(III))H2O](2+) species are irradiated with energies corresponding to the (1)A(1g) --> (1)A(2g) and (1)A(1) --> (1)A(2) transitions.