Highly sensitive flexible pressure sensors are at the forefront of the development of future mobile applications, such as rollable touch displays, health monitoring, and electronic skin. Recently, monolithic organic field-effect transistors (OFETs) combined directly with pressure-sensitive components have been demonstrated as actively workable pressure sensors due to cost-effectiveness, good flexibility, and large-area solution processing, which effectively enables conformal large-area contact with a surface. Despite many pioneering efforts, the low cost and easy fabrication of OFET devices cannot be fully exploited without the development of OFET-based pressure sensor printing processes. In this presentation, we will introduce a highly sensitive pressure sensor based on a printed OFET with centro-apically self-organized organic semiconductor microstructures. Unlike previously reported OFET-based pressure sensors prepared with a top microstructured dielectric layer, we designed a unique OFET bottom layer consisting of semiconductor channels positioned at the highest summit of printed cylindrical microstructures, referred as “3D OSC”. This unique microstructure was achieved simply by printing an organic semiconductor and a polymer blend, which self-organized after deposition without additional process. The proposed 3D OSC OFET pressure sensors demonstrated a high pressure sensitivity of 1.07 kPa−1 and a rapid response time of <20 ms with a high reliability over 1000 cycles. We demonstrated that our sensors are applicable to the real-time monitoring of radial artery pulse waves and as touch sensors for use in realistic prosthetic hands.