Jeddah Islamic Port authorities thwarted an attempt to smuggle 8.735 million pills of amphetamine, known as Captagon, in a shipment of cocoa beans, the Saudi Press Agency said on Sunday.
Three people were arrested. Drug traffickers face capital punishment if found guilty in Saudi Arabia.
The kingdom is believed to be the Middle East's largest market for the drug. There are often reports of attempts to smuggle Captagon pills in shipments of fruits and vegetables.
A cache of 2.14 million pills was recently discovered in a shipment of tomato paste going through the Al Haditha border crossing.
Such instances have prompted Saudi Arabia to stop importing fruits and vegetables from Lebanon, which is said to be one of the manufacturing hubs of Captagon in the region. The other is Syria.
In the first three months of this year alone, Saudi Arabia said it thwarted attempts to smuggle some 90 million amphetamine pills, 7.9 tonnes of hashish and 5.5 kilograms of cocaine.
Being illegal, Captagon is often interlaced with other chemicals, including caffeine. It allows users to stay awake and remain focused for long hours at a time, making it a popular choice for low-income individuals and students.