Col Misfir Al Qarini, of the General Directorate of Border Guards, said the operation resulted in the seizure of a large amount of several types of drugs. He said it was carried out by land and sea patrols in Jazan, Najran, Asir, Al Jawf, and Tabuk.
A video posted on the Saudi border guards' Twitter account shows several seized bags filled with drugs.
The drug bust also resulted in the arrest of 120 suspects of different nationalities, including 40 Saudi citizens. The remaining 80 suspects are from Yemen, Ethiopia, Egypt, Jordan, Somalia and Pakistan.
Initial legal measures were taken against them, Col Al Qarini said, and the seized goods were handed over to authorities.
Trade in the amphetamine-type stimulant Captagon in the Middle East grew last year to more than $5 billion, said a report by the New Lines Institute, raising fears of an increasing health and security risk to the region.