Two types of lanthanide- acetate-chloride hydrates, [M(CH3COO)(H2O)6]Cl2 · H2O (M La-Sm) and [M(CH3COO)2(H2O)3]Cl (M Ce-Lu, Y), are obtained by the reaction of the chloride hydrates MCl3 · xH2O (x = 7, 6) and the oxychlorides MOCl respectively with and in acetic acid (solution). The first compound type contains cationic dimers o∞{[M(CH3COO)(H2O)6]2}4+ and is therefore called “type 0” (0 for zero dimensional). The characteristic structural feature of the latter is a cationic chain 1∞[M(CH3COO)2(H2O)3]+; it is a “type 1” compound (1 for one dimensional). All compounds were characterized by X-ray powder diffraction (Guinier method) and their thermal behaviour was investigated by thermal analysis.