Titanium aluminide alloys based on the intermetallic α 2 phase, Ti 3 Al, are potential replacement materials for conventional titanium and nickel alloys in future gas turbine engines. This paper describes work carried out on the creep behaviour of two Ti 3 Al alloys, Ti-23Al-9Nb-2Mo-0.9Si and Ti-23Al-9Nb-2Mo-2V-0.9Si, tested in the temperature range 650-750 o C. Results are compared with the conventional titanium alloy IMI834. The Ti 3 Al-based alloys have greatly enhanced creep strength, the equivalent of up to 90 o C increase in temperature capability. Creep strain accumulation has been modelled using the Graham-Walles equation, and predictions show a good fit to the experimental data over the full range of temperatures and stresses. For given creep life, the Ti 3 Al-based alloys have a relatively high primary creep strain, which must be considered during component design if the alloys are to be used to their full potential.