By using ab-initio density functional theory and the Perdew-Burke-Ernzerh of generalized gradient approximation, the Young's modulus of double-wall boron nitride nanotubes (DWBNNT) is investigated. We estimated the value of the Young's modulus of (2,2) BNNT into (7,7) BNNT ((2,2)@(7,7) DWBNNT) and (2,2) BNNT into (9,9) BNNT ((2,2)@(9,9) DWBNNT) Y=821 GPa and Y=764 GPa, respectively. Theoretical value of 4.45 eV was obtained for the band gap energy of DWBNNTs. The calculated Young's modulus for armchair nanotubes is compared to the existing experimental and theoretical data. (C) 2013 Elsevier B.V. All rights reserved.