He, Ne, Ar, Kr and Xe are computed to be bound inside C-60 by -0.3, -1.9, -2.5, -7.5 and -5.4 kcal/mol, respectively, at the counterpoise-corrected MP2/6-31G(**) level (using a DZP basis for Kr and Xe). Even though the basis-set superposition error is still quite large at this level, it seems remarkable that there is no destabilization even for Xe@C-60. Unlike He-3, which is shielded by -6 ppm in He@C-60,Xe-129 is predicted to be deshielded in Xe@C-60 (by ca. +60 to +70 ppm) and also in the higher fullerene compounds Xe@C-70 and Xe@C-84 (by smaller amounts). (C) 1997 Elsevier Science B.V.