Polymer semiconductors are very promising materials for future organic based electronics such as flexible displays, electronic papers, photovoltaic devices and integrated circuits. The most important reason of using polymer is that polymer films can be easily obtained using low-cost processes such as spin-coating, ink-jet printing and rubber stamp printing. Particularly, the rubber stamp printing has received considerable attention lately because this technique does not require any photolithographic process during the device fabrication and direct printing of various films are possible. Recently, metal lamination technique using a rubber stamp has been reported by Loo et al. which enables direct printing of metal thin films on a plastic substrate. In this approach, with combination of polymer film printing technique, all-printed electronics will be possible on various kinds of substrates. In this report, we demonstrate organic field-effect transistors (OFETs) fabricated using the rubber stamp printing method. The poly (3-hexylthiophene) (P3HT) active channel layer was printed with a pre-patterned rubber stamp eliminating any photolithographic process required for patterning the polymer layer. Also, it is expected that printed polymer films have different molecular ordering structure compared to spin coated films due to the unique film formation mechanism in rubber stamp printing. To analyze and compare the molecular ordering of the spin coated and printed polymer films, synchrotron grazing-incidence X-ray diffraction (GI-XRD) measurements were carried out. Through the investigation of the molecular ordering of rubber-stamp-printed P3HT films, the printed films showed preferential orientation of (100)-axis normal to the film surface or edge-on structure providing high field-effect mobility.