This review presents the achievements of the last 10-15 years in interzeolite transformations as a method for synthesizing high-performance zeolite catalysts. The main regularities and mechanisms of interzeolite transformations are analyzed. The paper describes a variety of examples where interzeolite transformations ensured a successful synthesis of zeolite structures which either could not be prepared from amorphous sources or required the use of expensive templates. The advantages of zeolite catalysts synthesized by interzeolite transformation, compared to those obtained from amorphous sources, are demonstrated.