The structural, lattice dynamical, and some thermodynamical properties of TcB2 in hexagonal AlB2-type structure (Hex-I) (space group P6/mmm), hexagonal ReB2-type structure (Hex-II) (space group P63/mmc) are investigated using first-principles calculations. The phonon dispersion curves are derived from the direct method. The present results show that this compound is dynamically stable for considered structures. The temperature-dependent behavior of thermodynamical properties such as internal energy, free energy, entropy, and heat capacity are also presented and trends are discussed. (C) 2012 Elsevier Masson SAS. All rights reserved.