This paper reports the results of an experimental determination of the secondary‐emission characteristics of glycerol layers on copper surfaces. This work has as its motivation the use of glycerol as a working fluid in electric thrustors for spacecraft.Secondary‐emission coefficients for glycerol are reported as a function of incident primary‐electron energy. Primary‐electron energy was varied from 200–900 eV and glycerol secondary‐emission coefficients were found to vary from 2.5 to about 1.0. These results are compared with values for clean copper surfaces found by using the same apparatus.