The aircraft went on to serve in the Regia Aeronautica as a long-range bomber and patrol aircraft, but by World War II, the last S.55s were no longer serviceable and were in reserve.
Letoun pokračoval ve službě v Regia Aeronautica jako dálkový bombardér a hlídkový letoun, na začátku druhé světové války již poslední S.55 nebyly provozuschopné a byly uloženy v rezervě.