Using temperature dependent X-ray diffraction on two InSb single crystalline substrates, the bulk lattice constant of InSb was determined between 32 and 325 degrees C. A polynomial function was fitted to the data: alpha(T) = 6.4791 + 3.28 x 10(-5) x T + 1.02 x 10(-8) x T-2 angstrom (T in degrees C), which gives slightly higher values than previously published (which go up to 62 degrees C). From the fit, the thermal expansion of InSb was calculated to be alpha(T) = 5.062 x 10(-6) + 3.15 x 10(-9) x T K-1 (T in degrees C). We found that the thermal expansion coefficient is higher than previously published values above 100 degrees C (more than 10% higher at 325 degrees C). (c) 2013 Elsevier B.V. All rights reserved.