  Collisional energy loss of a fast particle in a medium is mostly due to the
medium polarization by the electromagnetic fields of the particle. A small
fraction of energy is carried away by the Cherenkov radiation. In chiral medium
there is an additional contribution to the energy loss due to induction of the
anomalous current proportional to the magnetic field. It causes the particle to
lose energy mostly in the form of the \emph{chiral} Cherenkov radiation. We
employ classical electrodynamics, adequate in a wide range of particle
energies, to compute the collisional energy loss by a fast particle in a
homogenous chiral plasma and apply the results to Quark-Gluon Plasma and a Weyl
semimetal. In the later case photon spectrum is strongly enhanced in the
ultraviolet and X-ray regions which makes it amenable to experimental
investigation. Our main observation is that while the collisional energy loss
in a non-chiral medium is a slow, at most logarithmic, function of energy $E$,
the chiral Cherenkov radiation is proportional to $E^2$ when the recoil is
neglected and to $E$ when it is taken into account.
