Note that all expats may only be married in Portugal according to Portuguese law. There are no consular marriages at Embassies or at any of the Consul
The Portuguese authorities require the following:
As a temporary resident, you must take your passport with you, and as a permanent residence you have to bring your residence card along.
Both of you must provide copies of your birth certificates that were issued within the last six months. Unless your wedding takes place in the Azores, then the documents may be issued within the last three months.
A certificate of no impediment must also be shown. This can be applied for at a consulate in Lisbon, Oporto, Portimão, Funchal or Ponta Delgada. The certificate is valid for three months from the date of issue. If it is obtained in a country outside Portugal, it may be translated into Portuguese at the corresponding consulate.
For a wedding in a Roman Catholic Church, you have to provide baptismal certificates.
Once you receive approval, your wedding has to take place within three months.