The work output capacity of the two-way shape memory effect (TWSME) in a Ni _50.3 Ti _29.7 Hf ₂₀ (at%) high-temperature shape memory alloy (HTSMA) was investigated and compared to that of binary Ni _49.9 Ti _50.1 (at%). TWSME was induced through a training procedure of 100 thermomechanical cycles under different tensile stresses. It was observed that TWSME in as-extruded and trained Ni _50.3 Ti _29.7 Hf ₂₀ could produce 0.7% strain against a compressive stress of 100 MPa, corresponding to a maximum work output of 0.08 J g ⁻¹ , compared to a maximum value of 0.06 J g ⁻¹ for binary NiTi. A peak aging heat treatment of 3 h at 550 °C, which previously has been shown to result in near-perfect functional stability in Ni _50.3 Ti _29.7 Hf ₂₀ during isobaric thermal cycling, did not improve the TWSME and actually resulted in a decrease in the magnitude and stability of the TWSME and its work output capacity. Nevertheless, the magnitude of TWSM behavior of Ni _50.3 Ti _29.7 Hf ₂₀ , in the absence of an aging heat treatment, renders it an attractive candidate for high-temperature TWSM actuation.