By 1936 Moscardó had reached the rank of colonel. At the beginning of the Spanish Civil War he took control of the Alcazar School of Infantry. Surrounded by the Republican Army, Moscardó and despite threats to his captured son, refused to surrender.
When the siege came to an end, Moscardó took command of the troops at the battle of Guadalajara (March 1937). He also took part in the Nationalist campaign in Aragón and led the Army of the Aragon during the campaign in Catalonia.
After the war Moscardó was promoted to lieutenant general and became captain general of Catalonia (1943-45). The following year he became captain general in Andalusia.
José Moscardó died in 1956.