This paper presents a substantial review of the preparation and implementation of carbon nanotubes (CNTs) for piezoresistive strain-sensing applications. CNT has been a breakthrough material among flexible electronics, and over the last two decades, it has been thoroughly studied and evolved in terms of its fabrication and utilization techniques. The enhanced electromechanical characteristics of CNT allow researchers to produce high-quality sensors for various applications. One of its critical applications is piezoresistive sensors. Indeed, the responses of thin film CNT-based sensors towards applied micro- and macroscale pressures have provided crucial information to the involved application. The significance of piezoresistive sensing is constantly rising in this era of flexible microelectronics. For example, vital physiological signals can be detected through small-scaled structural changes of the sensing prototypes. Sensors like these have been fabricated with a range of process materials and can be deployed for biomedical applications. A review of the exploitation of CNT-based sensors for piezoresistive activities is showcased here. Some common techniques to fabricate CNTs are also mentioned, in addition to the classification of piezoresistive sensing prototypes based on single-walled and multi-walled CNTs.