A number of 1:2 or 1:1 Ag(I)X:L complexes formed between silver(I) salts, Ag(I)X, and P-donor ligands (L) PPh(3-n)mesn (‘mes’ = 2,4,6-trimethylphenyl) have been synthesized and spectroscopically and structurally characterized. Ag(I)X:Pmes3 (1:2) (solvated) are of the ionic form [Ag(Pmes3)2]+X−, with linear two-coordinate silver atom environments; for X = C1O4−, CF3SO3− (= 'tfs−'); with X = NO3−, the 1:1 complex [(mes3P)Ag(O,O’–NO3)] is obtained but with Ag(I)tfa ('tfa−' = CF3CO2−), [(mes3P)Ag(O,O'-tfa)(NCMe)] has been defined, incorporating MeCN solvent. The 1:2 adducts with PPhmes3/NO3− and PPh2mes3/C1O4−, tfs−, NO3−, tfa−, ac− (=CH3CO2−), SCN− are all of the form [(X-O,O’)AgL2] (unidentate SCN excepted). Ag(I)I:PPhmes2 (1:1) takes the 'cubane' tetramer form, while Ag(I)SCN:PPh2mes (1:1) adopts the (expanded) chair tetramer alternative. A remarkable Ag(I)I:PPh2mes adduct has been isolated, being of 4:3 (x2) Ag(I)I:L stoichiometry, comprising a pair of Ag4I4 cubane units each with three associated phosphine ligands, fused through a central Ag4I4 four-membered ring, the array being centrosymmetric.