  The Li\'{e}nard equation is of a high importance from both mathematical and
physical points of view. However a question about integrability of this
equation has not been completely answered yet. Here we provide a new criterion
for integrability of the Li\'{e}nard equation using an approach based on
nonlocal transformations. We also obtain some of previously known criteria for
integrability of the Li\'{e}nard equation as a straightforward consequences of
our approach's application. We illustrate our results by several new examples
of integrable Li\'{e}nard equations.
