The optical properties of binary and ternary germanate glasses 40.3GeO2-59.7PbO, 31.3GeO2-26.8PbO-41.9Bi2O3 and 31.5GeO2-40.4PbO-28.1Bi2O3 (wt%) doped with Er3+ were investigated. The Judd-Ofelt intensity parameters were calculated and the near-infrared luminescence as well as the upconversion efficiency was analyzed. We observed that the ternary germanate glass containing the highest concentration of Bi2O3 presented the largest emission bandwidth for 4I13/2 → 4I15/2 transition and the highest infrared-to-visible upconversion efficiency among the samples studied. These results demonstrate that not only the presence of Bi2O3 but also the careful choice of its molecular weight plays a key role in optimizing parameters for using germanate glasses for photonics applications. © 2006 Elsevier B.V. All rights reserved.