The fabrication of a poly(3,4-ethylenedioxythiophene) (PEDOT) pattern is demonstrated. As template, an n-octadecyltrichlorosilane (OTS) monolayer self-assembled on indium tin oxide (ITO) was structured by UV–ozone photolithography, resulting in an ITO–OTS patterned surface. The conducting properties of the ITO were utilized for the selective electropolymerization of 3,4-ethylenedioxythiophene (EDOT), whereby the electropolymerization was inhibited by the insulating OTS. Differently sized PEDOT–OTS patterns were obtained. The electronic properties of the patterns were finally evaluated in a test OLED device.