We report the successful growth of InAs/Ga1−xInxSb strained‐layer superlattices, which have been proposed for far‐infrared applications. The samples were grown by molecular beam epitaxy, and characterized by reflection high‐energy electron diffraction, x‐ray diffraction, and photoluminescence. Best structural quality is achieved for superlattices grown on thick, strain‐relaxed, GaSb buffer layers on GaAs substrates at fairly low substrate temperatures (<400 °C). Photoluminescence measurements indicate that the energy gaps of the strained‐layer superlattices are smaller than those of InAs/GaSb superlattices with the same layer thicknesses, in agreement with the theoretical predictions of Smith and Mailhiot [J. Appl. Phys. 62, 2545 (1987)]. In the case of a 37 Å/25 Å, InAs/Ga0.75In0.25Sb superlattice, an energy gap of 140±40 meV (≊9 μm) is measured. This result demonstrates that far‐infrared cutoff wavelengths are compatible with short superlattice periods in this material system.