The soldier came under attack during a joint patrol with Afghan forces in the Murghab valley in the northwestern Badghis province on Monday, AFP quoted the Italian military as saying.
According to the report, two soldiers were also injured in the assault, one of them critically.
The fatalities of Italian soldiers have reached to 41 since the beginning of the deployment of Italian troops in Afghanistan in 2003.
Italy has some 4,200 troops in war-stricken Afghanistan, mostly deployed in Kabul and Herat.
The increasing number of troops casualties in Afghanistan has caused widespread anger in the US and other NATO member states, undermining public support for the Afghan war.
According to official figures, at least 2,607 US-led soldiers have been killed in Afghanistan since the US-led invasion of the country in 2001.