The method of electron microscopy is used to investigate the morphology and crystallography of M5B3 borides in creep-resistant nickel alloys with -5 wt% Cr and 10-12% W, and 15-20% Cr with 3-5% W. The morphological varieties of the borides, their orientation relation with the (γ + γ′)-matrix, and the influence of segregational, phase and structural inhomogeneity on the boride distribution in the volume of the alloys are described.