We measured the volume thermal expansion of Ti3SiC2 from 25 degrees to 1400 degrees C using high-temperature X-ray diffraction using a resistive heated cell. A piece of molybdenum foil with a 250 mu m hole contained the sample material (Ti3SiC2+Pt). Thermal expansion of the polycrystalline sample was measured under a constant argon flow to prevent oxidation of Ti3SiC2 and the molybdenum heater. From the lattice parameters of platinum (internal standard), we calculated the temperature by using thermal expansion data published in the literature. The molar volume change of Ti3SiC2 as a function of temperature in degrees C is given by: V-M (cm(3)/mol)=43.20 (2)+9.0 (5) x 10(-4)T+1.8(4) x 10(-7)T(2). The temperature variation of the volumetric thermal expansion coefficient is given by: alpha(v) (degrees C-1)=2.095 (1) x 10(-5)+7.700 (1) x 10(-9)T. Furthermore, the results indicate that the thermal expansion anisotropy of Ti3SiC2 is quite mild in accordance with previous work.