The Second World War was a testing time for Radio Éireann but technological developments in the 1940s would make radio production more flexible.

The Second World War (known as 'The Emergency' in Ireland) was a testing time for Radio Éireann. Censorship was rigorously enforced over all the Irish media between 1939 and 1945 under the Emergency Powers Act and, as a state run service and accessible overseas, Radio Éireann broadcasts received particularly close attention.

War reporting was censored because of the policy of neutrality. Bulletins prepared by the tiny newsroom staff consisted of extracts from official communiqués without any comment. Before being broadcast, these news bulletin scripts were read over the phone to Head of the Government Information Bureau, Frank Gallagher. Before 1939, Mr Gallagher had been Assistant Director at Radio Éireann: he was now its censor.

Neutrality brought other changes. All three Radio Éireann transmitters at Dublin, Cork and Athlone were synchronised onto a single frequency - this measure was intended to prevent the transmitters being used for direction-finding by aircraft.

Furthermore, there was a prohibition on broadcasting weather forecasts, which were regarded as strategically important. Apart from the ongoing annoyance for farmers and fishermen, this policy meant, for example, that a sports commentator would have to omit an innocent phrase such as "it's a lovely day here today in Dublin for the football final".

Operations were also restricted by difficulties in obtaining the necessary parts to keep transmitters running.

Censorship brought in under the Emergency Powers Act was lifted on 11 May 1945.