High-quality KTiOPO4 (KTP) crystals were grown by a top seeded solution growth (TSSG) method using K8P6O19-BaF2 as a flux. The volatility of different solvents, such as K8P6O19 (K-8), K-8-NaF, K-8-KF, and K-8-BaF2, was measured. These fluoride additives in K-8 fluxes and their compositional effects on the growth of KTP crystals were studied and discussed. The transmissivity and optical homogeneity of KTP crystals were also measured. (C) 2009 Published by Elsevier B.V.