The paper supported Vizcaya's young Conservative Party and its editorial line was clerical, Alfonsist monarchist, free press and Basque regional autonomist.

It was almost a year later, on 6 July 1937, when the paper published again, after the fall of Bilbao; it was joined on newsstands by El Correo Español, the official newspaper of the Falange Española Tradicionalista y de las JONS, the Spanish fascist party, using the seized presses of the Basque nationalist daily Euzkadi[citation needed].

The year 1965 saw El Correo move to its current offices in Calle Pintor Losada, convert to tabloid format and increase the number of pages.

In 1976, El Correo for the first time surpassed La Gaceta del Norte in sales, becoming the best-selling newspaper in northern Spain.

Also around this time, publisher Javier de Ybarra y Bergé was kidnapped and murdered by rogue elements of the Basque separatist organization ETA.

[9] The editor-in-chief of El Correo is Juan Carlos Martínez Gauna[10] and its publisher is Bilbao Editorial.