Abstract: Polynomial identity algebras (or PI-algebras) can be seen as generalizations of both commutative and finite dimensional algebras which maintain many ``nice'' properties. In this talk, we give a short introduction to Lie PI-algebras, focusing on the study of multilinear identities. Using these techniques, we demonstrate the existence of an identity for Lie algebras having certain actions on them; such actions arise naturally, for example, when the Lie algebra is graded by a finite group.