  We calculate radiative energy loss of heavy and light quarks in anisotropic
medium (static) in first order opacity expansion. Such an anisotropy can result
from the initial rapid longitudinal expansion of the matter, created in
relativistic heavy ion collisions. Significant dependency of the energy loss on
the anisotropy parameter ($\xi$) and the direction of propagation of the
partons with respect to the anisotropy axis is found. It is shown that the
introduction of early time momentum-space anisotropy can enhance the fractional
energy loss in the direction of the anisotropy, whereas it decreases when the
parton propagates perpendicular to the direction of the anisotropy.
