Detailed dilatometric study of the sintering behaviour of equiatomic Ti-Ni elemental powder has been carried out the under controlled atmosphere. Two different activation energies, 200.9 and 46.2 kJ/mol were observed in a lower and higher temperature range, indicating sintering to be controlled by the solid state inter-diffusion and the chemical reactions. Sintered product shows the reversible austenitic and martensitic transformations. © 2005 Elsevier Ltd. All rights reserved.