Latest figures show that almost one in 12 properties sold last year were bought by non-residents, who were responsible for 12 percent of the total spend.
Foreign buyers also spent an average of 160,000 euros on each real estate transaction, while local buyers averaged just over 107,000 euros.
Real estate transactions involving non-residents increased by just under 20 percent in number, and were up almost 23 percent in value.
Topping the list of nationalities are French nationals, representing one in five sales, followed by the UK (16.2 percent), Brazil, China and Switzerland.
The majority of sales were in the Algarve, with 42.8 percent of the national total involving non-residents, followed by Lisbon with 35 percent. The Portuguese capital was however, where foreign buyers spent the most on real estate, with average sales averaging 276,000 euros.
In related news, foreign tourists visiting Portugal have spent close to 11 billion euros on services during the first eight months of the year.
According to tourism figures out this week, the trend established up until August could see 2018 setting a new record in terms of cash left behind by tourists while visiting the country.
The current record, set last year, currently stands at 15 billion euros.