Upon coming to St Petersburg in 1759, Gudovich joined the Russian Army, hoping to benefit from the favors enjoyed by his elder brother, Andrey, an aide-de-camp to Peter III.

Thereupon Gudovich moved to the Caucasian front, where he stormed the most important Ottoman stronghold, Anapa, and took prisoner its garrison of 13,000 soldiers.

While he was on his furlough, the Empress died and her successor Paul, recalling Ivan's allegiance to his father, had Zubov replaced with Gudovich, who was also made count.

By that time, the Persian expedition was over and Gudovich prepared to lead the Russian armies to combat Revolutionary France on the Rhine.

Named commander-in-chief in the Caucasus in 1806, Gudovich led the Russian armies to the Caspian Sea during the Russo-Persian War (1804–13), overrunning the khanates of Derbent, Sheka, and Baku on his way.