The outbreak of the War of the Second Coalition found Mittrowsky serving in the army of Italy under Pál Kray. He fought at the drawn Battle of Verona on 26 March 1799. A little over a week later, he led a brigade in Karl Mercandin's column at the Battle of Magnano. During the Battle of Novi in August 1799, his brigade fought with the left wing under the overall supervision of Michael von Melas. Mittrowsky was elevated in rank to Feldmarschall-Leutnant in October 1799.