She undertook duties in the North and South Atlantic Ocean, Adriatic, Mediterranean, Caribbean and Baltic Seas throughout her time in service, and completed several patrols to the Persian Gulf and deployments to the Far East.

1994 saw her return again to the Gulf but this time visiting Singapore, Penang, Tioman Island and Sri Lanka whilst off station.

En route back from the Far East, the ship took the opportunity to stop and lay a wreath at the site of the sinking of the previous HMS Cornwall, a County Class heavy cruiser sunk by Japanese dive bombers in April 1942.

In 2003 she was again committed to Standing Naval Force Atlantic, supporting Operation Active Endeavour in the Mediterranean Following the death of the Princess of Wales in 1997, the role of sponsor was assumed by Mary Holborow, Lord Lieutenant of Cornwall.

On 23 March 2007, fifteen sailors and Royal Marines from HMS Cornwall were detained by elements of the Navy of the Army of the Guardians of the Islamic Revolution following a routine search of a vessel suspected of smuggling, in the vicinity of disputed territorial waters.