We perform a renormalization group transformation to construct perturb
atively a lattice theory of chiral fermions. The field variables of th
e continuum theory are averaged over hypercubes to define lattice fiel
ds, Integrating out the continuum variables we derive a chirally invar
iant effective action for the lattice fields. This is consistent with
the Nielsen-Ninomiya theorem because the effective action is nonlocal.
We also construct the axial current on the lattice and we show that t
he axial anomaly of the continuum theory is reproduced in the Schwinge
r model.