  The charge form factor of $\pi$ and $K$ mesons is evaluated adopting a
relativistic constituent quark model based on the light-front formalism. The
relevance of the high-momentum components of the meson wave function, for
values of the momentum transfer accessible to $CEBAF$ energies, is illustrated.
The predictions for the elastic form factor of $\pi$ and $K$ mesons are
compared with the results of different relativistic approaches, showing that
the measurements of the pion and kaon form factors planned at $CEBAF$ could
provide information for discriminating among various models of the meson
structure.
