The former Sporting Lisbon boss will remain in the role until 2016, taking him beyond the European Championships that year.
"Our criteria for evaluating the performance of the national team coach is not just restricted exclusively to the results, although we can't hide that they are an important part of any coach's objectives," said Portuguese federation president Fernando Gomes.
"We are very satisfied in continuing a project which has borne fruit not just for the senior team but for the national teams at other age levels."
Bento added: "I'm very proud and honoured to continue serving my country.
"I believe I can continue to be useful in developing a project involves more than anything else obtaining results for the senior team but which has a strategic side which I enjoy very much."
Bento took over the Portuguese national team in September 2010, guiding them to the semi-finals of the European Championships two years later.