Applying for a Portuguese passport can be a lengthy and challenging process. Two considerations are necessary before you begin the process. First, if your parents are, or were, of Portuguese origin, one of both must be listed in the Registo Civil Portugues. Registration can be retrospective. Second, if you were a resident in the ex-Portuguese territories of Africa between January 1974 and December 1975, you don't qualify to apply for a Portuguese passport.
The necessary documents are birth certificates for yourself, spouse and children if they apply with you; your marriage license; valid identification for all applicants, such as a current passport; full address; recent passport photographs; and birth, marriage and death certificates (if applicable) of your parents and grandparents.
The latter is necessary because applicants must prove they have origins in Portugal. If you don't include the documents regarding parents and grandparents, your application certainly will be delayed and perhaps rejected.
Additional Documents for Goa, India, Applicants
Some applicants from the region formally known as Antigo Estado da India and now known as Goa, India, are required to observe specific criteria.
If you were born before Dec. 18, 1961, you don't need additional documents.
If you were born after Dec. 18, 1961, however, you are required to prove that your parents were born and married in the region.
If your parents married after Dec. 18, 1961, or outside Antigo Estado da India, it's necessary to ensure that one or both parents are listed in the Registo Civil Português. Again, registration can be retrospective.
Translation to Portuguese
All documents must be translated into Portuguese. If they are submitted in any other language, they will be rejected. Translations should be factored into the application cost before you submit your application to avoid a stall once you're committed to the process.
It is strongly advisable to engage an attorney or immigration professional to manage the process on your behalf because eligibility criteria can change quickly.
Portugal allows dual nationality. The other country involved, however, may not welcome dual nationality.
Passports can be applied for at any Portuguese embassy. Some may require an appointment. It's also advisable not to make travel plans before your passport is issued because most embassies take only special circumstances, such as the death of a family member, into consideration when processing an application. Contacting the nearest Portuguese embassy is wise before submitting your application.