Gunfire from Syrian territory targeted a Jordanian patrol close to the border at 1900 IST yesterday in the Jabieh area, an army statement said.
"One patrol member was lightly injured and received treatment at the scene. The border guards returned fire, killing one assailant and wounding two more."
Jordan is one of five Arab countries supporting US-led air strikes against the Islamic State jihadist group in neighbouring Syria.
The kingdom has upped surveillance along the 370 kilometre shared border and has arrested dozens of people trying to cross illegally from Syria.