Abstract The influence of crystal orientation, melt height, and crystal rotation rate on the shape of the crystal/melt interface for LiNbO3 was investigated. While the crystal orientation and the melt height has little influence on the interface shape, the shape was found to be strongly affected by the crystal rotation rate. Above a critical rate, inversion from a convex to a concave interface occurs. The critical rate is inversely proportional to the crystal diameter. A comparison between critical rotation rates for LiNbO3 calculated by relations predicting such rates and those obtained by growth experiments is given.