The effect of doping with scandium, zirconium, and hafnium on the thermal stability of high-strength wrought Al–Zn–Mg–Cu (of 7XXX series) alloys at 80^oС for 100 hours is investigated. The study is performed on rods produced by a two-stage hot extrusion of 1500 g ingots. As shown, the doping with scandium and zirconium has improved the hardness and strength characteristics due to the occurrence of two ensembles of dispersed precipitates: intermetallics η'-phase (MgZn₂) and Al₃(Sc_1-xZr_x) particles coherently bonded with the aluminium matrix. As proved, in the 7XXX alloy, which is additionally doped with the (Sc + Zr + Hf) complex, the composition of nanosize precipitates based on Al₃Sc intermetallic compound includes zirconium and hafnium. The alloying of the base alloy with the complex (Sc + Zr + Hf) stabilizes the structural state of the alloy and, after holding at 80^oС, no significant changes in the size and distribution of strengthening particles are observed. This makes it possible to obtain high strength characteristics of Al–Zn–Mg–Cu alloys with a high level of plasticity at long-term holding at 80^oС.