Secondary electron yields δPE due to primary electrons of kilo-electron-volts are estimated for various metals by measuring total electron yields δT in an UHV system and using a Monte Carlo calculation to derive δPE from δT. The dependences of δT/δPE as well as δPE on both the atomic number Z and primary energy are also discussed from a theoretical viewpoint based on the Monte Carlo technique for primary energies higher than a few keV and on a simple theory for lower primary energies.