Following the entry of the U.S. into the war it was realized that there was an insufficiency of aviation training facilities, both in the U.S. as well as in France. This condition coincided with the need for additional need for aircraft designed by European manufacturers. This dual need was partially addressed by having both the A.E.F. Air Service and the U.S. Navy have pilots trained in Italy. In exchange, Italy was going to provide aircraft for the American personnel to fly. The result was that the Italians provided training facilities for A.E.F. pilots. These pilots, following training, served both with Italian units or were transferred to the Western Front in France. The U.S. Navy operated at traing facility at Lake Bolsena and operated a naval air station on the Adriatic.

The Caproni ca.5, or Caproni 600 hp, was designed in 1917 as a replacement for the old and effective Ca.3 bomber. This powerful bomber was the object of a huge production plan, ansd it was expected that it would form huge masses of Allied bombers. It was ordered to Caproni (800 bombers) Mianbi-Silvestri (900) Breda (600) Bastianelli (600) Officine Reggiane (300) San Giorgio Pistoia (250) and Piaggio (200). Large factories were set up for its production, but by the end of the war only a few dozens were actually built by Caproni.

During tests and early operational life, the type was found highly unsatisfactory. The Fiat A 12 powered version suffered constant problems for bad manufacturing standards and poor integration of the engines. The first Ca.5s were assigned to the 1a Squadriglia Navale, an élite Naval unit commanded by the famous poet Gabriele d'Annunzio, but despite the constant pressure of the hero, the teething problems of the Ca.5 were never eradicated, and the 1a SA never used it in operations.

Meanwhile the standard squadrons, lacking Ca.3s, whose production had been stopped, were running short of aircraft. The Isotta Fraschini powered version of teh Ca.5 was reportedly less unsatisfactory, but still far below the required level.

The first operative unit to use the Ca.5 was the 6a Squadriglia that received some of them in August 1918, passing its Ca.3s to other units. On 27 October 1918 6 aircraft took off from Tombetta for an action over Vittorio Veneto, during the final Italian offensive. The Caproni Ca.5 11669 with the crew of American pilots Coleman Fenafly De Witt and lt. James Bahl and the Italians lt. obs. Vincenzo Cutello and serg. Tarcisio Cantarutti was attacked and shot down by five Austrian fighters, with oberleutnant Roman Schmidt and Emmerich von Horvath. Lieutenant De Witt was posthumously awarded the Medaglia d'Oro al Valor Militare (gold medal for bravery) Italy's highest award, assigned to just 23 airmen in the war.

A large quantity of Caproni 6 was produced for the US Navy and in late 1918 they were ferried by American pilots from Milan to Northen France, suffering severe mishaps. Their use by the Northern Bombing Group was minimal.

After the war, production of the Ca 600 was stopped, when parts for hundreds of these now useless bombers were filling up the warehouses. It was considered to transform the Ca.5 into an airliner, but one of them crashed in August 1919, killing 17 people, most of them journalists, in the worst air accident ever. Another plan was to adapt it to the use of three SPA 6a 200 hp engines and use it as a general purpose aircraft in Africa, but the plan was abandoned, and the Ca.5 quickly disappeared from Italian airfields, missed by nobody, while the Ca.3 soldiered on for another decade.