The mononuclear adducts chloro - and bromo-pyridinebis (triphenylphosphine)silver have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. The two complexes are isomorphous, monoclinic, space group P21 or P21/m, a 蠹.8, b 蠲0.0, c 蠹.1 Š, ߠ蠹7.5ꬠZ 2; in space group P21/m, they were refined to residuals of 0.038, 0.036 for 2392, 2157 'observed' reflections respectively. No comparable iodide adduct has been isolated. In both structures the silver atom is four-coordinate; Ag-Cl,Br are 2.511(2), 2.629(1) Ż Ag-P, 2.472(1), 2.476(1) Ŭ and Ag-N, 2.585(5), 2.570(5) Šrespectively, the Ag-N distance being longer than Ag-P, indicating very weak coordination of the pyridine.