Cristescu was promoted to lieutenant (1890), captain (1894), major (1902), lieutenant colonel (1907), and colonel (1910). He became Chief of the Romanian General Staff on 2 December 1913, and served in this role until 1 April 1914. He played an important role in the development of the operational plans of the Romanian Army in the years prior to the entry of Romania in World War I, including the "Hypothesis Z" plan. He was promoted to brigadier general in 1914.