Biopolymer nanoparticles can be used as key and versatile components in colloidal delivery systems that have numerous food and pharmaceutical applications. Various methods have been employed for the fabrication of biopolymer nanoparticles. However, many conventional methods are infeasible for the synthesis of biopolymer nanoparticles because they involve energy-, time- and, material-consuming protocols. The use of miroemulsions is a novel and alternative approach for the synthesis of biopolymer nanoparticles. The composition and structure of microemulsions can be optimized to tailor nanoparticle characteristics. In this review, different microemulsion-based procedures for the synthesis of biopolymer nanoparticles are discussed, including single and double microemulsion-based methods. The major parameters affecting the size of biopolymer nanoparticles are also summarized. In addition, current challenges and future research directions in the preparation of biopolymer nanoparticles using reverse microemulsions are discussed.