Abstract
In this thesis we reproduce the results of Laca and Neshveyev for characterizing certain KMS states on Pimsner algebras. Before getting there, we build up the necessary theory using various sources, giving detailed proofs along the way. This includes preliminary results about traces and the construction of the Pismner algebras. Finally we apply the theory to give a more streamlined presentation and shorter proofs of the results about KMS states on Pimsner algebras of self-similar groups by Laca, Raeburn, Ramagge and Whittaker.