CNT-based nanofluids have been shown to have the highest thermal conductivity when compared to other types of nanofluids. As a result, the CNT-based fluid is now regarded as a new generation of nanofluids, attracting researchers to investigate its thermophysical properties and potential applications in a variety of heat transfer applications. However, there is a disparity in the data for thermophysical properties, and different claims about its long-term stability have been made. This work attempted to comprehend a broader field of study on the thermophysical characteristics of CNT-based nanofluids, which could aid the scientific community in making further advances in the field of CNT-based nanofluids. The synthesis, characterization, and experimental findings on the thermal conductivity and viscosity of CNT-based nanofluids are all included in this paper. Numerous factors influencing thermal conductivity and viscosity are thoroughly discussed. Additionally, numerous models for predicting the thermal conductivity and viscosity of nanofluids based on CNTs are investigated. The current work suggests the use of ANN models that can account for many factors in setting the correlation for thermal conductivity and viscosity and are accurate in predicting results. Apart from thermophysical properties, the hazardous effect of CNT on human health and the contribution of different works in the CNT usage for improving the performance of a solar collector are summarized to provide insightful information on advancement in this field. The study recommends standardization in CNT nanofluid preparation and thermophysical property measurement to eliminate disparity in results.