In this article various nanorefrigerants have been critically reviewed towards the performance enhancement of the refrigeration system. Research has been more focused on the different techniques to prepare nanorefrigerants. This paper is an attempt to summarize all aspects of nanorefrigerants such as preparation, thermophysical properties, hydrodynamic study, boiling heat transfer, and performance of nanorefrigerants. It also discusses the effects of different nanoparticles on thermophysical properties. Nanorefrigerants are a special category of nanofluid, advanced nanotechnology-based refrigerants that are stable mixtures of nanoparticles and base fluid, which improve thermophysical properties such as heat transfer and pressure drop and bring compactness to the system. This article presents an overview of improving thermal performance by using different nanoparticle blends with different base refrigerants. Further, influential parameters of nanoparticles and thermal performance are discussed. This paper also discusses the effects of different nanoparticles such as Al₂O₃, TiO₂, CuO, carbon nanotubes (CNTs), etc., on thermophysical properties. The present situation requires a robust system and refrigerants for required performance. Some refrigerants cannot be used directly. So, this paper deals with using nanorefrigerants for better system performance such as coefficient of performance (COP) enhancement, compressor work reduction, and energy efficiency. It is seen that the use of nanorefrigerants, or nanotechnology-based refrigerants, results in highly effective cooling and thus enhances the thermophysical properties of refrigeration systems.