Excellent quality crystals of CsLiB6O10 (CLBO) up to 60 x 45 x 20 mm(3) in size have been grown from supercooled melts at constant temperature. The observed variations in habit for crystals grown from different seed orientations may be explained by assuming that CLBO crystallises in an ideal tetragonal bipyramidal form bounded by 8 {1 0 1} faces. Several linear and non-linear optical parameters were determined including the temperature dispersion of refractive index which is described in detail for the first time. The measured type I phase matched second- and fourth-harmonic generation parameters compare favourably with the values calculated from the refractive index data and those reported by previous authors. (C) 1998 Elsevier Science B.V. All rights reserved.