In this paper, we study the effects of the configuration of two Al atoms doped into the unit cell of (7,0) BNNTs, on their structural and electronic properties in solid state using density functional theory methods. Also, all possible configurations for Al double doped (7,0) BNNT were investigated. The results showed that with Al doping, band gap decreased. Furthermore, an impurity state appears near the Fermi level when two Al atoms replace two boron atoms of adjacent layers. Contour plots of charge density distribution showed a protuberance surrounding N and B atoms adjacent to the substitute Al atoms. (C) 2016 Elsevier B.V. All rights reserved.