In a previous paper, we reported that the reaction of cerium metal in 2-methoxyethanol yielded a transparent colloidal solution of ultrafine (2 nm) ceria particles [M. Inoue, M. Kimura, T. Inui, Chem. Commun., 957 (1999)]. In this paper, the solvothermal reaction of other rare-earth metals in 2-methoxyethanol has been examined. Reactions of Sm and Yb metals in 2-methoxyethanol at 300 degrees C yielded transparent colloidal solutions of Sm2O3 and Yb2O3 particles. However, the reaction of rare-earth metals of Y, Eu, Gd, and Tb in 2-methoxyethanol at 300 degrees C resulted in recovery of the starting materials. Transparent colloidal solutions of the oxides of these elements were obtained by reaction in the presence of a small amount of acetic acid. The solvothermal reaction of rare-earth metals in 2-aminoethanol was also examined.