The Public Prosecution Service is a body of the Portuguese State, which is composed of a set of magistrates.

In the criminal proceedings, the Public Prosecutor has several functions:
• Receive crime reports and complaints and initiate the criminal proceedings.
• Lead the investigation operations and guide the police’s collection of evidence during the investigation phase.
• Assess the evidence collected in the investigation phase and decide whether it is sufficient to prosecute the defendant.
• At trial, they sustain the accusation being made against the defendant by presenting the evidence they collected: witnesses, experts, documents, and more.
• After the sentencing, they present an appeal against any decision with which they do not agree. For example, the Public Prosecutor can appeal the judge's decision to acquit the defendant at the end of his trial.
• One of the most important functions of the Public Prosecutor is to inform victims of crime about their rights and how they can be exercised, such as the right to be supported, to file a complaint/ report the crime they suffered, to apply for legal aid if they don’t have the financial means to pay the trial costs, to request compensation from the offender, etc.

The offices of the Public Prosecution Service are usually located in court buildings.