As a rule, the answer is no. Holding a residence permit issued by Portugal does not automatically grant the right to work in another Member State of the European Union.
A foreign national legally residing in Portugal may travel within the Schengen Area for short stays. Under the Regulamento (UE) 2016/399, such stays are limited to 90 days within any 180-day period. However, this regime concerns only the right of entry and short-term stay, typically for tourism, family visits, or business meetings. It does not, in itself, include the right to carry out professional activity, whether employed or self-employed.
In short, freedom of movement is not the same as freedom to work.
The right of third-country nationals to work is primarily regulated by the law of the Member State where the activity is carried out. Therefore, a person residing in Portugal who intends to work in another country (such as Spain, France, or Germany) must comply with that country’s legal requirements, including obtaining the appropriate visa or work permit. A Portuguese residence permit produces legal effects essentially within Portuguese territory and does not function as a general EU-wide work authorization.
A residence permit issued in Portugal allows short-term travel within the Schengen Area but, by itself, does not grant the right to work in other EU countries. Anyone wishing to work outside Portugal must, in principle, obtain authorization from the destination country, unless covered by a specific EU mobility regime.