Recent work performed at Onera on nickel-based superalloys for disk applications is presented. In the first section, disk characteristics and metallurgical routes used to produce these specific aero-engine components are reviewed. Then, two alloy development programs carried out to satisfy the requirements of the industrial partners are detailed. Finally, the results of studies aiming at identifying the complex relationships linking the microstructure and the creep behaviour of disk superalloys are described: influence of the strengthening γ’ precipitation on the deformation micromechanisms, and effect of the microstructure on grain boundary sliding.