The Monday night phone call comes a fortnight after Khan had called up the Saudi Crown Prince to inform him about India's move to revoke the special status of Jammu and Kashmir.
Both the leaders discussed a host of issues including the ongoing Kashmir crisis. Khan briefed the Saudi royal about the situation in Jammu and Kashmir, said Pakistani media reports.
The Crown Prince's phone call came as US President Donald Trump spoke with Khan and Indian Prime Minister Narendra Modi and urged both sides to defuse tensions over Kashmir.
Trump also told the Pakistani leader to "moderate the rhetoric with India" over Kashmir.
On August 7, Khan had called up the Saudi royal over Kashmir. The two leaders had "discussed the development of the situation in the region and efforts exerted towards it", the Saudi Press Agency (SPA) said.
"The Crown Prince was also briefed by the Pakistani Prime Minister on the latest developments in Kashmir," it added.