The effect of sonication on the process of electrooxidative polymerisation of salicylic acid and on the resulting passivating film is described. A new example of the formation of a microarray electrode by the sonication of the polymeric film is presented. It is shown that in the sonicated electrochemical cell different areas can be found in which two different mechanisms by which ultrasound affects the electrochemical process take place, i.e. acoustic streaming and microjetting.