The building was badly damaged in World War II; it was restored with a much simpler façade and re-opened in 1950 with Wagner's opera Die Meistersinger von Nürnberg. Notable directors included Erwin Piscator, Jean-Louis Barrault, Heinz Dietrich Kenter, Hansgünter Heyme. Caspar Neher became head of design in 1927 and designed here eight operas and 11 plays.
In 1988, the role of the Grillo-Theater as Essen's major stage venue was taken by the newly constructed Aalto Theatre which also opened with Die Meistersinger. Following a major reconstruction by the architect Werner Ruhau and a reduction of the auditorium from 670 to 400 seats, the Grillo-Theater became a flexible smaller venue; it re-opened in September 1990 with Shakespeare's A Midsummer Night's Dream.