Graphite intercalation compounds (GICs) with the trichlorides of Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu have been prepared and characterized by chemical analysis and X-ray diffraction. Attempts to synthesize binary GICs with LaCl3, CeCl3, PrCl3, and NdCl3failed. By heating mixtures of YCl3+ LnCl3(Ln = La - Lu) with graphite ternary GICs were obtained. The molar ratios LnCl3:YCl3in the GICs were found to increase from La to Dy which runs parallel to the decrease in the ionic radii of the Ln3+ions.