The average cross section for the reaction 63Cu(n, α)60Co has been measured absolutely in the 252Cf spontaneous fission neutron field by activation in compensated flux geometry with an accuracy of ∼2.4% (1α). A near-point source of 252Cf and a light mass source-detector assembly in a low-scattering environment was used. The resulting cross-section value was compared with calculated values obtained by convoluting the spectral distribution of 252Cf neutrons with existing energy-differential data for the reaction 63Cu(n, α)60Co. There is very good agreement (within 5%) between the experimental and the calculated average cross section if the results from a recent measurement of the 63Cu(n, α)60Co excitation function are used. Thus the reaction 63Cu(n, α)60Co, which is an important threshold reaction in reactor dosimetry, fulfills the conditions for a Category I neutron-dosimetry reaction for fission reactor applications.