The current from the surfaces of metals exposed in vacuum to 60Co gamma radiation was measured to determine the electron emission. The metals were in the form of solid cylinders 1.27-cm (0.50-in.) diam × 10.2 cm (4.0 in.) long. The electron emission factors increased smoothly with atomic number Z, varying from (3.06 ± 0.63) × 10-17 A/cm2 per rad/h (absorbed dose) for carbon to (18.2 ± 0.4) × 10-17 A/cm2 per rad/h (absorbed dose) for lead.