Silver nanoclusters in poly(methyl methacrylate) (Ag/PMMA) were prepared by bulk polymerization of MMA with radical initiators (AIBN or BPO) in the presence of silver(I) trifluoroacetate, followed by a period of UV irradiation. It was revealed that any of Ag/PMMA samples prepared by both the initiators shows a plasmon absorption peak at ca. 420 rim, whereas an additional peak at ca. 340 nm was found exclusively for those samples prepared in the presence of BPO.