The study focused on optimization of growing conditions of new nonlinear optical crystal BaAlBO3F2 (BABF). Using LiF-B2O3-NaF system as fluxes, inclusion-free BABF single crystal with sizes up to 25 x 20 x 16 mm(3) had been successfully grown by the middle-seeded solution growth technique. Solubility data of BABF was measured in the range of 746-860 degrees C. Preparation process of starting materials, flux selection and optimization of other growing parameters were discussed in the paper. The morphology of BABF was also studied. (c) 2008 Elsevier B.V. All rights reserved.