Ipswich's long-serving mayor Paul Pisasale has resigned, citing his battle with multiple sclerosis as the reason, one day after the state's crime and corruption watchdog raided the council office.

Dressed in pyjamas and a dressing gown, Mr Pisasale made the announcement at St Andrew's Hospital in Ipswich.

"Now it's my time to look after my health," he told reporters.

Within hours of his announcement, the Crime and Corruption Commission released a statement confirming it had executed a search at Ipswich City Council on Monday.