The conducting polymer poly(3,4-ethylenedioxythiophne) (PEDOT) is widely used as channel material for organic electrochemical transistors (OECT), due to its mixed ionic-electronic conductivity, chemical stability and biocompatibility. The study presented here aims to explore and optimize the fabrication of OECTs by electropolymerization of the monomer, EDOT, bridging the gap between microfabricated source and drain electrodes. Various types of dopants, namely poly(styrenesulfonate), perchlorate, hexafluorophosphate and tetrafluoroborate were used. The channel length and the deposition time were also varied to control the channel dimensions. These parameters were chosen to study their impact on overall film morphology and uniformity, which are known to strongly affect electrical properties, and hence, transistor behaviour. The electropolymerization, which is a relatively simple technique, could therefore be used to fabricate OECTs in bioelectronics.