The thermal-neutron capture cross section and capture resonance integral for 10.7-year 85Kr have been determined in carefully monitored experiments using 99.992% isotopically pure 85Kr. Values of 1.66 ± 0.20 b and 1.8 ± 1.0 b for the thermal-neutron cross section and resonance integral, respectively, were derived from the increase in 86Kr produced during the irradiation and measured mass spectro-metrically. We conclude from our results that the burnup of radioactive 85Kr in power reactors as a possible means of disposal is not feasible.