In their simplest form, filhós are traditional Portuguese deep-fried treats prepared with leavened dough. They come in numerous regional varieties that may differ in form and often incorporate different spices and additions such as pumpkin or orange juice.

After frying, they are usually coated in cinnamon sugar, and in Algarve, they are occasionally dipped in brown sugar syrup. Although they are often associated with Christmas, filhós are enjoyed all year round. In some regions, the term filhós may refer to the round Portuguese-style doughnuts that are better known as malasadas.