The affect of boron (B) on the microstructure and creep behavior of a Ti-15Al-33Nb (at%) alloy was investigated. In addition to the normal constituent phases present in the monolithic alloy, the B-modified alloy contained borides enriched in titanium and niobium. These borides were present in the form of needles/laths up to 50 μm long and 10 μm wide which took up 5-9% of the volume. Constant load, tensile-creep experiments were performed in the stress range of 150-340 MPa and the temperature range of 650-710°C, in both air and vacuum environments. An addition of 0.5 at% B did not improve the creep resistance of the monolithic alloy, while the addition of 5 at% B significantly improved the creep resistance.