Previous measurements of secondary electron emission from vanadate‐phosphate glasses, using extremely clean surfaces, suggest that where these materials are used in practice as secondary emitters, surface contamination by materials such as cesium plays an important role. Samples of glasses containing significant quantities of cesium in the initial melt were manufactured, and did indeed show increases of 50% or more in the secondary electron emission yield. The yield increased monotonically with cesium content for all samples tested. The inelastic reflection coefficient for these materials was high—about 0.2. Similar materials containing sodium rather than cesium behaved very similarly where the V2O5content was 60% or more, although the reflection coefficient was lower—about 0.1. Where the V2O5content was less than 60%, however, high sodium concentrations produced a drastic fall in yield. V2O5‐P2O5‐Cs2O or V2O5‐P2O5‐Na2O glasses are easily manufactured by the same techniques as V2O5‐P2O5materials, and in view of their increased secondary electron emission coefficient, they should prove useful as secondary emitters in a variety of applications.