Hydrido complexes [MnH(CO)3L1–3] [L1 = 1,2‐bis‐(diphenylphosphanoxy)‐ethane (1); L2 = 1,2‐bis‐(diisopropylphosphanoxy)ethane (2); L3 = 1,3‐bis‐(diphenylphosphanoxy)‐propane (3)] were prepared by treating [MnH(CO)5] with the appropriate bidentate ligand by heating to reflux. Photoirradiation of a toluene solution of complexes 1 and 2 in the presence of PPhn(OR)3–n (n = 0, 1; R = Me, Et) leads to the replacement of a CO ligand by the corresponding monodentate phosphite or phosphonite ligand to give new hydrido compounds of formula [MnH(CO)2(L1–2)(L)] [L = P(OMe)3 (1a–2a); P(OEt)3 (1b–2b); PPh(OMe)2 (1c–2c); PPh(OEt)2 (1d–2d)]. All complexes were characterized by IR, 1H, 13C and 31P NMR spectroscopy. In case of compounds 2 and 3, suitable crystals for X‐ray diffraction studies were isolated.