The fabrication and spectroscopic characterization of Ho3+ and Yb3+ codoped phosphate glasses, also containing silver nanoparticles (SNPs), is reported. The nucleation and formation of nanoparticle structures in the samples are confirmed using transmission electron microscopy analyses. It is found that the Ho3+Yb3+ SNP phosphate glasses exhibit an enhancement of both the resonantabsorption and the fluorescence properties when the SNP concentration is increased