  We have studied the anomalous behaviour of isotopic shifts of Pb nuclei in
the relativistic mean field theory. It has been shown that the relativistic
mean field provides an excellent description of the anomalous kink in the
isotopic shifts about $^{208}$Pb. This is in contrast from density-dependent
Skyrme forces which do not reproduce the observed trend in the empirical data
on the charge radii. We discuss some differences in the description of isotope
shifts in the RMF theory and the Skyrme mean field.
