In this paper, a novel polymer optical fiber (POF) sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. The plantar pressure signals are detected by five FBGs, in the same piece of CYTOP fiber, which are embedded in a cork insole for a dynamic monitoring of gait. The calibration and measurements performed with the suggested system are presented, and the results obtained demonstrate the accuracy and reliability of the sensing platform to monitor the foot plantar pressure distribution during gait. This architecture does not compromise the patient’s mobility nor interfere in their daily activities. The results showed a great response when compared with solutions using silica optical fibers, where a sensitivity almost two times higher, repeatability and easy of handling were achieved using the CYTOP fiber. The advantages of POF (e.g. high flexibility and robustness) proved that this is a viable solution for this kind of application, since POFs’ high fracture toughness enable its application in monitoring patients with higher body mass than the ones that a system based on silica fiber is capable of enduring. This study has demonstrated the viability of the proposed system based on POF technology as a useful alternative for plantar pressure detection systems.