Titanium aluminide alloys were prepared from cold-extruded elemental Ti and Al powders with compositions ranging from 25 to 75 at % Al. The production route in this study includes four essential steps : mixing, precompaction, cold-extrusion and reaction treatment. During reaction treatment, the intermetallic phases Ti3Al, TiAl and TiAl3 are formed by interdiffusion of Ti and Al, and pore formation takes place because of the different diffusivities of Ti and Al, The processes of phase formation, as well as pore formation, were studied by means of calorimetric, dilatometric and metallographic methods. In order to obtain nearly fully dense specimens, the technique of hot isostatic pressing was applied. The sintering behaviour and microstructures of the prepared alloys are reported.