In production for a mere three years (1955–1958), the series was built at the Lokomotivbau Elektrotechnische Werke works — commonly shortened to LEW — in Hennigsdorf, East Germany. During this time, 34 units were produced with the intention for use as a mixed traffic locomotive – hence its EU designation – though the reality is that the EU20 saw more use as a freight locomotive than a passenger one. EU20s were the first electric locomotives to be used on the route between Warsaw and Silesia.
The class gained notoriety for its frequent breakdowns involving the overheating of resistors, due to the lack of additional cooling facilities found in other locomotives.
During the series' 26-year service, most units were assigned to the Piotrków Trybunalski depot. EU20s were withdrawn over a 6-year period, beginning in 1976, with the last locomotive being withdrawn in 1981.