The electrochemical behavior of halogenocomplexes of Ag was investigated in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) in the presence of the corresponding halogen anion. Silver halides, AgX (X- = Cl-, Br-, and I-) were found to be soluble in BMPTFSA containing 0.5 M BMPX by forming [AgX3]2-. The cathodic reduction of [AgX3]2- to metallic Ag was possible within the electrochemical window of BMPTFSA. The reduction potentials were in the order of [AgCl3]2- > [AgBr3]2- > [AgI3]2-. The morphology of Ag deposits depended on the reduction potential. The diffusion coefficients of [AgCl3]2-, [AgBr3]2-, and [AgI3]2- were 2.5, 2.0, and 1.6 × 10-7 cm2 s-1, respectively. Formation of Ag nanoparticles dispersed in the ionic liquids was confirmed after potentiostatic cathodic reduction at -2.5 V using transmission electron microscopy.