The figures, from Tourism Research Australia's International Visitor Survey, also revealed that regional Victoria had a 15.9 per cent increase in the expenditure of international overnight visitors - reaching $313 million.

City of Ballarat destination and connections director George Sossi said day trippers were by far Ballarat's biggest tourist demographic.

He said they also formed the biggest percentage of Sovereign Hill's patrons, whose strongest market was Asian visitors.

Mr Sossi said being down 600 people, or 3.1 per cent, was not overly concerning because the figures were quite small.

"We know the overnight visitor market to Ballarat for internationals is challenged because we're so close to Melbourne," he said.

"We also find these sorts of figures come out quarterly, which can fluctuate quite dramatically."

Mr Sossi said there was no way to measure the number of day trippers who visited the city, because many came via wholesale coach tours to visit places like Sovereign Hill and Ballarat Wildlife Park.

"There is no measurement that captures that as a whole, and the major way is through the tourism operators themselves," he said.

Victoria had its largest-ever share of international overnight visitors, with 30 per cent of those who visited Australia last year coming to Victoria.

This was despite the Black Saturday bushfires, swine flu and the global financial crisis.

Some of Victoria's biggest increases were from Malaysia, which was up 38.1 per cent, India (up 26.1 per cent) and Singapore (up 10.1 per cent).