Portugal - Passport & Nationality - Portuguese Citizenship by Birth
at least one of the parents is Portuguese; OR
at least one of the parents was born and resided in Portugal at the time of birth; OR
he/she (or his/her legal guardian) declares that he/she wants to adopt the Portuguese nationality and provided that (i) the parents are not at the service of their State of origin and (ii) at least one of them has been residing in Portugal for a period of 5 years or more; OR
he/she does not possess any other nationality.