Inaugurating the event, Croatian Agriculture Minister Bozidar Pankretic said the congress provided an opportunity for Croatia to show what it could offer in the viticulture and wine sector.
The congress can help Croatia to promote its economy, notably its wine brands and tourist trade, said Pankretic.
He said that Croatia had increased its vineyard hectarage from 28,394 hectares in 2000 to 33,741 in 2008.
Last year, Croatia produced 1.27 million hectolitres of wine, with riesling and malmsey being the main sorts.
Peter Hayes, president of the International Organisation of Vine and Wine (OIV), said Croatia had a great potential for the development of the grape and wine industry and wine tourism.
Asked by reporters about the impact of the ongoing economic crisis on the grape and wine industry, Hayes said that big companies had seen a fall in profits, while small producers and wineries were more flexible in adjusting themselves to the current situation.
The congress lasts until 3 July, and on its last day, the OIV will hold a convention at which it will elect its new president.