The effect of rare-earth ion dopants La, Cc and Nd on the growth aspects and ferroelectric properties of triglycine sulphate single crystals is reported. The incorporation of dopants into the grown crystals is far below the concentration in the mother solution. The dopants significantly modify the morphology of the crystals. Dielectric measurements revealed that the dielectric constant of Cc doped triglycine sulphate (TGS) increases rapidly at the transition temperature. Well-saturated rectangular hysteresis loops have been observed for all the doped crystals. Lenticular ferroelectric domain patterns were observed on the [0 1 0] plane of the grown crystals. Among the three dopants, La doped TGS possess a high Curie temperature and coercive field values. (C) 2002 Elsevier Science B.V. All rights reserved.