Crystals of a family of compounds, ABe(2)BO(3)F(2) (ABBF, A = K, Rb, Cs, Tl), have been grown hydrothermally. Each of these materials was studied using the powder SHG technique and exhibited promising NLO behavior. Seeded crystal growth was demonstrated and the growth conditions were optimized by modifying the temperature, thermal gradient and mineralizer concentration. RbBe2BO3F2 crystals possessed a particularly good combination of SHG intensity, favorable crystal habit and fast growth rates. High quality crystals suitable for advanced deep-UV NLO studies were grown at rates of 0.11 mm/day on (001) and 0.12 mm/day perpendicular to (0 0 1). (c) 2007 Published by Elsevier B.V.