A 29-year-old Polish soldier died when a mine exploded on a road in southeastern Afghanistan on Wednesday, Poland's defence ministry said.
Pawel Ordynski, whose vehicle struck the mine in the province of Ghazni, is the 39th Pole to die in a decade of conflict in Afghanistan, ministry spokesman Jacek Sonta said.
Poland has 1,800 troops serving in Afghanistan with NATO's International Security Assistance Force (ISAF), making it one of the main contributors to the 100,000-strong mission.
The Polish unit, deployed there since 2002, is currently responsible for security in Ghazni.
Polish Foreign Minister Radoslaw Sikorski told parliament on Wednesday that Poland would downsize its Afghanistan troops to 1,000 soldiers in October.
International coalition forces are to exit Afghanistan by the end of next year, leaving local forces to take on fighting the Taliban alone.
One other Polish soldier has died in Afghanistan this year, killed in January during a joint counter-terrorism operation with Afghan forces.