Single crystals of BaNaB9O15 (BNBO) have been grown by the Czochralski pulling method in air. This compound was investigated for nonlinear optical applications and was expected to exhibit an extended transparency window in the ultraviolet. The transmission spectrum of the crystal obtained is reported. The refractive indices were measured by the minimum deviation technique and fitted to the Sellmeier equations. The phase matching (PM) angle for type I SHG of 1064 nm Nd:YAG laser was calculated to be theta = 58.0 degrees. Because BNBO possesses a very weak effective nonlinear optic coefficient and admits neither third-harmonic generation (THG) nor FHG of 1064 nm laser, it is not interesting as a nonlinear material for UV light generation. (c) 2008 Elsevier B.V. All rights reserved.