"Giulio Cesare" began an extensive reconstruction in October 1933 at the Cantieri del Tirreno shipyard in Genoa that lasted until October 1937. A new bow section was grafted over the existing bow which increased her length by to and her beam increased to . The ship's draft at deep load increased to . All of the changes made increased her displacement to at standard load and at deep load. The ship's crew increased to 1,260 officers and enlisted men. Two of the propeller shafts were removed and the existing turbines were replaced by two Belluzzo geared steam turbines rated at . The boilers were replaced by eight Yarrow boilers. On her sea trials in December 1936, before her reconstruction was fully completed, "Giulio Cesare" reached a speed of from . In service her maximum speed was about and she had a range of at a speed of .