  A class of exact solutions is obtained for the Li\'{e}nard type ordinary
non-linear differential equation. As a first step in our study the second order
Li\'{e}nard type equation is transformed into a second kind Abel type first
order differential equation. With the use of an exact integrability condition
for the Abel equation (the Chiellini lemma), the exact general solution of the
Abel equation can be obtained, thus leading to a class of exact solutions of
the Li\'{e}nard equation, expressed in a parametric form. We also extend the
Chiellini integrability condition to the case of the general Abel equation. As
an application of the integrability condition the exact solutions of some
particular Li\'{e}nard type equations, including a generalized van der Pol type
equation, are explicitly obtained.
