Belgium's traditional potato "frites" could soon be 3cm (1.1in) smaller than normal, growers have warned.
Pierre Lebrun, head of the Walloon Potato Growers' Association, said lower levels of rainfall had cut potato crop yields by 25 per cent.
"Because the potatoes are smaller at the moment, we will all be eating smaller chips," he told the Sudpresse newspaper.
"Frites" are a signature Belgian dish, often eaten with mayonnaise.
Lebrun said the dry ground also made farmers' work more difficult. "It's the same thing across southern England, the Netherlands, France and western Germany," he said.
Last month, the Guardian newspaper reported that Belgium has applied to the EU for emergency funds to deal with the drought.
"It is a disaster in the fields that the farmers could not irrigate. We record losses of around 30 per cent," Romain Cools, the secretary general of Belgapom, the country's largest potato grower, told the newspaper, BBC reports.
The "frite" is reputed to have originated in Namur in francophone Belgium, where the locals were particularly fond of fried fish. When the River Meuse froze over one cold winter in 1680, people are said to have fried potatoes instead.