In the first such case heard in court in France, the grain grower Paul Francois, 47, said he suffered neurological problems including memory loss, headaches and stammering after inhaling Monsanto’s Lasso weedkiller in 2004.
He blames Monsanto for not providing adequate warnings on the product label.
The ruling was given by a court in Lyon, south-east France, which ordered an expert opinion of Francois’s losses to establish the amount of damages.
“It is a historic decision in so far as it is the first time that a [pesticide] maker is found guilty of such a poisoning,” Francois Lafforgue, Francois’s lawyer, told Reuters.
Monsanto said it was disappointed by the ruling and would examine whether to appeal against the judgment.
“Monsanto always considered that there were not sufficient elements to establish a causal relationship between Paul Francois’s symptoms and a potential poisoning,” the company’s lawyer, Jean-Philippe Delsart, said.
Previous health claims from farmers have foundered because of the difficulty of establishing clear links between illnesses and exposure to pesticides.