A typical Portuguese name is composed of one or two given names, and two family names. The first surname is usually the mother's family surname and the second surname is the father's family surname; however, the order of the surnames can be reversed and it is common to find people with three or four surnames.
For practicality, usually only the last surname is used in formal greetings or in scientific papers indexing, but in a list of persons, the first given name, not the surname, is used for alphasorting. A married woman may add her husband's last surname(s) to the end of her own name, but this is not mandatory. The same may happen with men, though this is extremely rare.
Read more about Portuguese Name: General, Number of Names, Spelling of Names, The Name 'Maria', Surname and Marriage, The Particle 'de', Collation, Diminutive, Origin of Portuguese Surnames, Most Common Names in Portugal and Brazil, See Also