Physically unclonable functions (PUFs) are the important primitives in the field of hardware security [1] . Their applications would be further broadened if PUFs are fabricated using organic thin lm transistors (oTFTs) [2] , [3] . However, the rapid temporal degradation of the oTFTs deteriorates their performance. This paper proposes an organic current mirror PUF (OCM-PUF) that is fabricated on exible substrates [4] . The basic structure of the proposed circuit is a current mirror in which oTFTs share a gate electrode to self-compensate temporal degradation. The OCM-PUF is fabricated using bottom gate oTFTs to evaluate the metrics as a PUF. It achieved the randomness of 85.8%, the diffuseness of 98.4%, and the reliability of 76.4%. The response of the proposed PUF presented a high tolerance against the response change due to aging.