The crystallochemical and magnetic nature of ternary Sc 1+ δ Fe 4− δ Al 8 intermetallic with a small Sc excess δ=0.1 was investigated by scanning electron microscope, X-ray powder diffraction, neutron diffraction, Mössbauer effect and superconducting quantum interference device techniques. The sample crystallizes in a tetragonal ThMn 12 type structure. The excess of Sc atoms substitute Fe at the (8f) positions and have a pronounced effect on the magnetic properties. The experiments carried out in temperature range 4–320 K show that below 120 K the magnetic structure of the alloy forms a double cycloid with magnetic moments rotating according to the incommensurate in-plane wave vector, which is temperature independent up to 160 K. The value of Fe magnetic moment is close to 0.9 μ B atom −1 at 4 K. Temperature dependence of unit cell dimensions can be explained within the Debye–Grüneisen approximation.