Abstract An isothermal section for the Al–Cr–Fe system at 1000 °C has been experimentally determined. From metallography, electron microprobe analyses and X-ray investigations on quenched samples the phase equilibria in the Al-rich corner of this system were established. No ternary intermetallic phases were found. But the binary compounds—and here especially those intermetallic phases originating in the Al–Cr subsystem—have large solid solubility ranges for the third element. This has a marked influence on the lattice constants, which were determined for all phases. In addition two X-ray spectra are presented. One for Al 8Cr 5, where three quarters of Cr can be substituted by Fe and for Al 4Cr, which was found to have a different crystallographic structure than described elsewhere.