The yearlong investigation was capped by 15 raids that netted the South American country's largest seizure of cocaine and resulted in the arrest of Uruguayan, Paraguayan, Colombian and Bolivian nationals, Interior Ministry undersecretary Juan Faroppa said.
Faroppa estimated the drugs would have fetched some $9 million on the streets in Europe.
Authorities said about 480 pounds of cocaine were seized on Tuesday, and about 290 pounds in follow-up raids in and around the capital of Montevideo.
Anti-Narcotics Brigade director Julio Guarteche told reporters that more raids were possible, saying, "this has just begun."
The bust topped Uruguay's previous largest cocaine seizure — the 1995 discovery of 480 pounds of cocaine on a light plane that flew from Brazil to a clandestine runway in northern Uruguay.
This week's raids totaled five times the amount of cocaine seized in Uruguay all last year, authorities said.
Police said they also confiscated nearly $180,000 worth of dollars and euros, along with seven vehicles.
Faroppa said authorities were investigating an international ring suspected of trafficking drugs to Europe through Uruguay, adding that police also were trying to determine the origin of the cocaine as well as how it entered the country.