We have investigated the stability of the electrical performances in staggered organic thin film transistors (OTFTs) manufactured by using a CYTOP fluoropolymer as a gate dielectric, after the devices underwent reliability cycles in a high moisture and temperature controlled environment chamber. The results of such testing cycles showed a very high stability against the environmental conditions that might be related to the device top-gate structure, working as an efficient encapsulation, and to the hydrophobic properties of the fluoropolymer used as gate dielectric.