Field-effect mobilities and on/off current ratios have been determined for the organic field-effect transistors (OFETs) based on three kinds of poly(p-phenylenevinylene) derivatives. The best transistor performance has been obtained for poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEHPPV). The hole mobility and the on/off ratio obtained for the MEH-PPV OFET are 3.6 x 10(-4) cm(2)/Vs and 1.5 x 10(6), respectively. These OFETs operate stably in the atmosphere as well as in vacuum.