Police arrested six people and seized about $46 million-worth of methamphetamine in Subic Freeport Sunday, a police spokesman said.
The six were caught while loading travel bags and boxes at the port of Subic containing about 200 kilograms (440 lbs) of the stimulant methamphetamine hydrochloride, said Chief Inspector Roque Merdegia.
Subic is a former US naval base that was converted into a freeport shortly after the Americans pulled out in 1992.
Merdegia put the street value of the seized drugs at P2 billion (about $46 million).
The raid was the result of five months of undercover operations, Merdegia said, although no other details were made available.
Western governments have tagged the Philippines a major transshipment point of illegal drugs in the region.
The Philippine Drug Enforcement Agency (PDEA) has in the past acknowledged that drug lords have been known to finance the election campaigns of local officials in remote provinces.