In 1875, Prince Dadian-Mingrelsky was transferred to the Chevalier Guard Regiment and saw action as part of the detachment of General Iosif Gurko in Bulgaria during the 1877–1878 war with the Ottoman Empire. He was present at storming Tarnovo, Kazanlak, and Shipka Pass in 1877. For his conduct, Dadiani was awarded the Order of St. Vladimir, 4th Class, with band and a gold sword with the inscription "for courage". He was promoted to colonel on 30 August 1877. After the war, he withdrew to reserves with the promotion to major-general in August 1878 and finally retired from service with a privilege of wearing a uniform in October 1878.