  We extend earlier investigations of charge symmetry violation in the valence
quark distributions of the nucleon, and make similar estimates for the pion.
The sensitivity of pion-induced Drell-Yan measurements to such effects is then
examined. It is shown that combinations of $\pi^+$ and $\pi^-$ data on
deuterium and hydrogen are sensitive to these violations, and that the pion and
nucleon charge symmetry violating terms separate as a function of $x_\pi$ and
$x_N$ respectively. We estimate the background terms which must be evaluated to
extract charge symmetry violation.
