The combined order book is in excess of 3bn, including 565m of joint lead manager interest, the lead said.
The final spreads are in line with guidance of 242bp area and 324bp area respectively.
Earlier, the sovereign started marketing the deal with initial price thoughts of low 240s on the shorter tranche, which has 3bn outstanding, and low-to-mid 320s on the longer tranche, which has 2.5bn outstanding.
Pricing is expected on Wednesday via Barclays, Citigroup, Credit Agricole, JP Morgan, Nomura and Novo Banco.
Portugal is rated Ba1/BB+/BB+ (all stable).