  Medium modification of pion form factor has been evaluated in asymmetric
nuclear matter. It is shown that both the shape and the pole position of the
pion form factor in dense asymmetric nuclear matter is different from its
vacuum counterpart with $\rho$-$\omega$ mixing. This is due to the density and
asymmetry dependent $\rho$-$\omega$ mixing which could even dominate over its
vacuum counterpart in matter. Effect of the in-medium pion factor on
experimental observables {\it e.g.}, invariant mass distribution of lepton
pairs has been demonstrated.
