The reaction of silver acetate and silver nitrate with the new phosphinethiosemicarbazone ligand 2-(2-(diphenylphosphino)benzylidene)-N-ethylthiosemicarbazone (HLPEt) gave rise to the complexes [Ag(LPEt)](4)center dot 2MeOH (1) and [Ag-2(LPEt)(HLPEt)](2) center dot (NO3)(2) (3). Slow crystallization of the mother liquors obtained from the synthesis of 1 and 3 afforded suitable crystals of [Ag-2(LPEt)(HLPEt)](2)(CH3COO)(2) center dot 6MeOH (2) and [Ag-2(LPEt)(HLPEt)](2)(NO3)(2) center dot 2MeOH center dot 2H(2)O (4), respectively. Complexes 2 and 4 are tetranuclear silver clusters displaying a similar Ag4S4P4 core, but containing different sizes, conformations for the Ag4S4 metallacycles, and crystal packings. The four complexes are strongly luminescent in methanol solutions. A comparison between the emission bands of compounds 1-4 lead us to conclude that the luminescence is notably affected by the charge and the counterion of the cluster.