Two different types of all-organic, transparent transistors, namely Organic Thin Film Transistors (OTFTs) and Organic Electrochemical Transistors (OECTs), were fabricated on transparent, flexible plastic substrates by means of inkjet printing. In OTFTs the source, drain and gate electrodes were inkjet printed using a poly (3,4ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) solution, while a thermally sublimated layer of Parylene C acted as gate dielectric. Two kinds of organic semiconductors were used as active layers: 6,13-bis(triisopropylsilylethynyl) pentacene for p-type and N1400 for n-type OTFTs. For OECTs, all electrodes were also realized by inkjet printing deposition of a PEDOT: PSS solution. Electrical output characteristics of both kinds of devices are reported, demonstrating that the performances of our devices may be compared to those of transistors fabricated employing different realization techniques. (C) 2011 Elsevier B. V. All rights reserved.