A new nonlinear optical alumino-borate crystal BaAlBO3F2 (BABF) has been discovered. The BABF crystal with length of 13 mm has been grown for the first time using a modified middle-seeded growth method with NaF flux. BABF dependence of similar structure crystal KBe2BO3F2 which can be grown only with the thickness of 0.5 mm. The relationship between structure and properties of BABF is discussed. The crystal growth conditions and growth habits have been investigated. (C) 2003 Elsevier B.V. All rights reserved.