The event's organising body, the Tourism Industry Association, says the gathering will generate millions of dollars worth of new business over the next four days.
Association spokeswoman Ann-Marie Johnson said the Trenz travel expo was expected to pump more than $1.5 million of turnover into Queenstown and Southern Lakes area businesses.
"The benefits will be felt not just by Trenz suppliers, such as the caterer and venues, but by a raft of other local businesses, from hotels, restaurants and bars to petrol stations, retailers and taxis," Ms Johnson said.
Southern Lakes chairman Jeff Staniland, of Arrowtown, said the fair was a "win-win" for the region.
"For Queenstown there are benefits across most sectors of the economy in providing services to the Trenz event and all the visitor traffic it generates."
New Zealand tourism operators who exhibited at last year's Trenz, when it was held in Queenstown for the first time, reported their attendance secured $164 million worth of new business over 12 months, Ms Johnson said.
"Tourism is one of New Zealand's biggest export industries, earning almost $10 billion in valuable foreign exchange each year. Held annually, Trenz is vital in ensuring Destination New Zealand remains competitive and grows its share of the international tourism business."
A total of 308 invited international travel buyers will talk business and network with about the same number of leading Southern Lakes and New Zealand tourism operators.
About 30 international media and 30 domestic media will also attend, plus sponsors and VIPs, including the Prime Minister and Minister of Tourism John Key.
Trenz will sustain a hive of networking in the Queenstown Events Centre until Thursday.
Some of those national and international tourism delegates attending the Trenz tourism gathering in Queenstown this week have already found their way to Wanaka to get a taste of the district's attractions.
Wanaka companies Ridgeline Adventure and Eco Wanaka combined at the weekend to lead a small group of delegates on a Mou Waho Island cruise and nature walk, and on a safari on West Wanaka Station.
Ridgeline Adventure co-owner Mark Orbell said getting the Trenz delegates on an adventure was a valuable tool for promoting the area.
"It's all about raising Wanaka's profile," Mr Orbell said.
Many of this year's delegates are from the emerging and expanding Asian tourism markets of China, India and Malaysia.
Mr Orbell said this was the second Trenz conference his company had attended and he had got "wonderful feedback" after last year's event.
