A Saudi soldier was killed by shelling from across the Yemeni border on Friday, becoming the third death this week, the official SPA news agency reported.
The National Guard serviceman was killed in the Najran region, in the southwest, said the Saudi-led coalition carrying out air strikes against Shia Houthi rebels in Yemen.
Another soldier died from shelling along the border on Wednesday, and a civilian was killed in Najran three days earlier.
The latest cross-border barrages coincide with advances since late July by pro-government fighters who recaptured the southern city of Aden from the Iran-backed Houthi rebels.
On Tuesday, they also took back Al-Anad airbase north of Aden, using heavy armour supplied by the coalition after hundreds of Gulf Arab troops landed in the port city to bolster the fightback.
The Saudi soldier brings the number of people killed in shelling and skirmishes along the frontier with Yemen to more than 50 since the coalition campaign began on March 26.
Most of the casualties have been soldiers.
In Yemen, the United Nations says the war has killed nearly 4,000 people, half of them civilians.