Saudi King Salman bin Abdulaziz entered the hospital early Monday morning for medical examinations.
The Saudi News Agency quoted a statement by the Royal Court as saying that King Salman, 84, entered the King Faisal Specialist Hospital in Riyadh to perform some tests due to an inflammation of the gallbladder.
Before King Salman took office in Saudi Arabia in 2015, he has served as crown prince and deputy prime minister since June 2012.
King Salman has also served as governor of the Riyadh region for more than 50 years.