If you are traveling to Portugal on a flight to Lisbon and are interested in hiring a car for your holiday, you have a number of different options for car hire at Lisbon airport.
Many car hire companies, both international and domestic, offer rental cars at Lisbon airport. Among them are large, well-known enterprises like Avis, Budget, Europcar, Hertz, National, and Sixt Rent a Car. They all have car hire offices at the arrivals area in Lisbon airport.
There are also local Portuguese companies such as A A Castanheira and Auto Jardim that offer car hire at Lisbon airport. They sometimes offer very cheap car hire deals in Lisbon, but make sure to read the fine print before booking. Occasionally there are hidden charges for things like petrol that can turn a seemingly inexpensive car rental into a very pricey one.
If you do not plan to hire a car at Lisbon airport, there are other modes of transport to get you from the airport to the Lisbon city center, including taxis and buses. These are good options if you plan to stay in Lisbon for the whole time that you are visiting Portugal.